Kurzgesagt – In a Nutshell
Kurzgesagt – In a Nutshell
Embedded Files
Sources – Tattoo Laser Fun
Sources – Tattoo Laser Fun
We thank the following expert for their critical reading, feedback and corrections:
– Prof. Taro Kono
Tokai University School of Medicine, Japan
– One in four people with a tattoo regrets it, 25 million people in the US.
In 2024, roughly 30% (ca. 114 million) Americans had at least one tattoo. The rates of tattoo regret vary slightly between countries and surveys. In the US, the estimated fraction of tattooed people regretting at least one of their tattoos is between 24% and 33%. Based on 114 million tattooed people, this would correspond to roughly 28 million people in the US who regret at least one tattoo.
Data from the US:
#U.S. Food and Drug Administration (FDA). Think Before You Ink: Tattoo Safety. 2024
https://www.fda.gov/consumers/consumer-updates/think-you-ink-tattoo-safety
Quote: “Tattoos are more popular than ever. Polling and data suggest that about 30% of all Americans, and 40% of those aged 18-34 years old, have at least one tattoo.”
#Schaeffer K & Dinesh S. 32% of Americans have a tattoo, including 22% who have more than one. Pew Research Center. 2023
Quote: “38% of women have at least one tattoo, compared with 27% of men.
[...]
Most tattooed Americans do not regret getting a tattoo. But about a quarter (24%) say they ever regret getting one or more of their tattoos.”
#LaserAway. The Cities and States with the Most Tattoo Regret. Retrieved August 2025
https://www.laseraway.com/articles/tattoo-removal/most-tattoo-regret/
Quote: “Of Americans surveyed, 1 in 4 regret at least one of their tattoos.
Tattooed Americans are more likely to regret the placement or size of their tattoo than the imagery itself.
Women are more likely than men to regret at least one of their tattoos.
Residents in Alabama spend more money on their tattoos on average than any other state ($1,005.90).
Nearly 1 in 10 tattooed Americans admit to instantly regretting a tattoo once it was on their body.”
#Removery. Ultimate Facts Guide About Tattoo Removal. Retrieved August 2025
https://removery.com/tattoo-removal/laser-tattoo-removal-facts/
Quote: “These insights stem from Removery’s fusion of quantitative and qualitative methods. Our research draws from internal databases, clinical studies, and client surveys, as well as data spanning over 1.6 million tattoo removal treatments from 2019-2024 across the United States, Australia, and Canada. Rigorous statistical analysis, trend modeling, and privacy safeguards underpinned our approach."
Data from the UK:
#Aslam A, Owen CM. Fashions change but tattoos are forever: time to regret. Br J Dermatol. 2013
Quote: “A total of 213 (37%) patients regretted their tattoo (70 female, 143 male). The median duration of a tattoo before regret was 18 years compared with 12 years in those who did not regret. Other factors that correlated with an increased likelihood of regret were male sex, younger age at acquisition and application by an amateur artist.”
Data from Australia:
#McCrindle. Tattoos in Australia: Perceptions, Trends and Regrets. 2013
https://mccrindle.com.au/article/tattoos-in-australia-perceptions-trends-and-regrets/
Quote: “One third (34%) of Australians with tattoos say that they regret, to some extent, getting a tattoo. One in 7 (14%) have commenced or looked into tattoo removal.”
Data from Turkey:
#Altunay İK, Güngör İE, Ozkur E, et al. Tattoos: Demographics, Motivations, and Regret in Dermatology Patients. Indian J Dermatol. 2022
https://pmc.ncbi.nlm.nih.gov/articles/PMC10043702/
Quote: “Of 302 patients, 140 (46,4%) were females and 162 (53,6%) were men. The mean age was 28,3 ± 8,1 years (min-max, 16–62) for all study group, 53% of participants (n = 160) had at least one tattoo involving letters or number, 80 participants (26%) stated regret for at least one of their tattoos, and 34 of them (42,5%) had their unwanted tattoo removed or camouflaged with a new tattoo. The most common reason for regret was ‘not liking the tattoo anymore’.”
– Getting ink carved into your body permanently has exploded in popularity in the last few decades, especially among Millennials.
#Statista. Share of Americans with one or more tattoos as of 2021, by generation. 2024
https://www.statista.com/statistics/259601/share-of-americans-with-at-least-one-tattoo-by-age/
Quote: “According to a recent surveys conducted in the United States, tattoos were common the most among Millennials. Millennials represents that part of population born between the beginning of the 1980s and half 1990s. On the other hand, only 13 percent of respondents belonging to the Baby Boomer generation had at last one tattoo as of 2021. [...]
Share of Americans with one or more tattoos as of 2021, by generation”
#Schaeffer K & Dinesh S. 32% of Americans have a tattoo, including 22% who have more than one. Pew Research Center. 2023
Quote: “Adults under 50 are especially likely to have a tattoo. Some 41% of those under 30 have at least one, as do 46% of those ages 30 to 49. This compares with a quarter of adults ages 50 to 64 and 13% of those 65 and older.”
– This is all fine and good but as people age they often stop identifying with what their younger versions wanted on their skin forever. Or sometimes their tattoos simply just look ugly or aged badly.
Possible reasons for wanting to remove a tattoo of course differ from person to person, and can also be strongly influenced by age, local customs and life trajectories. Below, we have listed a few surveys exploring the most common reasons for tattoo regret in various regions of the world.
#TattooPathway. Navigating Tattoo Regret: Insights, Statistics, and Advice. 2024
https://tattoopathway.com/tattoo-regret-insights-statistics-advice/
Quote: “It’s early days here at the Tattoo Pathway, but our first small survey with 68 respondents from 16 countries reveals that almost 1 in 2 people (47%) have experienced tattoo regret at some stage.
[...]
Our survey showed 15 distinct reasons why people still regret their tattoos, but a few main reasons dominated:
Meaning has changed: 47% of survey participants reported regretting their tattoo because they feel differently about the meaning of the tattoo now compared to when they got it.
Placement: 41% regret their tattoo because of where they got it done on their body.
Technical: 41% regret their tattoo because they are not happy with how it looks technically.
Misaligned expectations: 41% regret their tattoo because it didn’t match their expectations or what they envisioned it would look like.
Artist input: 24% regret their tattoo because the artist had too much input into the design.
Other reasons reported include:
Not speaking up in the session about disliking the design.
Getting covered too quickly and wanting different things now.
Trying to fit in.
Being under the influence.
The tattoo developing a stereotype (e.g., tramp stamp).
The character of the tattoo artist.
Lack of consideration.
The future consequences of the tattoo.”
#Rivera FP. A Highlight on Reasons for Tattoo Regrets and Removal. Medical Lasers 2021
https://doi.org/10.25289/ML.2021.10.2.106
Quote: “This study aims to highlight some of the reasons for tattoo regrets. Herein, it evaluated the characteristics of patients seeking tattoo removal services at a South American specialized laser center.
[...]
This is a retrospective study of over 757 surveys, including patients who consulted for tattoo removal between August 2017 and February 2020. The surveys were conducted using questionnaires which were sent to the patients through email and WhatsApp messages.
[...]
More than half of the patients (51%) stated dissatisfaction as the main reason for erasing their tattoos. The second most common reason was a professional requirement (19.4%), and the third most common reason was to change to significant others (14.9%). Twenty-eight cases (3.7%) only searched to fade colors, re-tattooed or eliminate some tattoo sections. Four participants were seeing to erase their tattoos due to an allergic reaction to the tattoo pigments.”
#Mitwalli H, Alfurayh N. Tattoo Regret, Complications, and Removal: A Cross-Sectional Study among Tattooed Individuals in Saudi Arabia. Dermatol Res Pract. 2024
https://pmc.ncbi.nlm.nih.gov/articles/PMC11300047/
Quote: “A total of 42.5% of participants attempted to remove one of their tattoos. The most common sites for tattoo removal were the eyebrows (49.4%), upper extremities (35%), and lower extremities (16.9%). The most common reasons for tattoo removal were cultural causes (74%), poor tattoo art (35%), and tattoos received at a young age (33.8%).”
– And so today laser tattoo removal is booming, being as normalized as dentist appointments.
#Fortune Business Insights. Tattoo Removal Market Size, Share & Industry Analysis, By Procedures (Laser Procedures, Surgical Procedures, Dermabrasion, and Others), By Facility Type (Artist Studios, Dermatology Clinics, and Others), By End-User (Women and Men), and Regional Forecast, 2025-2032. Retrieved August 2025
https://www.fortunebusinessinsights.com/tattoo-removal-market-110418
Quote: “The global tattoo removal market size was valued at USD 1.13 billion in 2024. It is anticipated to grow from USD 1.29 billion in 2025 to USD 3.57 billion by 2032, exhibiting a CAGR of 15.60% during the forecast period. North America dominated the tattoo removal market with a market share of 35.92% in 2024. Moreover, the tattoo removal market in the U.S. is expected to grow significantly, reaching USD 1.06 billion by 2032. Increasing demand for laser-based and non-invasive removal treatments is driving market growth.
Tattoo removal has become one of the most popular medical aesthetic treatments in recent times. The growing trend of having body painting, tattooing, and other forms of body art and the increasing number of youngsters who prefer upgrading or regret the existing body art are driving the demand for tattoo erasing services.”
– We explained what a tattoo is in detail before, but in a nutshell: From the perspective of your cells your tattoo is a mountain range of colourful boulders, from small to building-sized. Injected deep into your dermis by violently ripping huge wounds with gigantic needles.
Your body is trying hard to destroy the tattoo, but the ink particles are way too large to be transported away and your immune cells can’t eat them. So they do the next best thing: Keeping the ink trapped in a prison of flesh. This is why tattoos remain forever, millions of your cells give their lives to keep the ink in place – when they die new ones take their place.
You can watch our video on the biology behind getting a tattoo here: https://www.youtube.com/watch?v=nGggU-Cxhv0.
We also compiled sources on the science underlying that video, you can find them here: https://sites.google.com/view/sources-tattoo-inside/
Below, we list a few key sources on what happens in your body when you get a tattoo. For more information, please consult the full source list for our other video, linked above.
#Grant et al. Tattoo ink nanoparticles in skin tissue and fibroblasts. 2015.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4464189/pdf/Beilstein_J_Nanotechnol-06-1183.pdf
Quote: “Thus, the needle penetrates the skin through the epidermis and into the papillary layer of the dermis, where the ink particles accumulate. As with any type of trauma to the dermis, the first response of the body is to stop the resultant bleeding to form a clot. Then the skin tissue swells (edema) followed by a migration of immune system cells to the wound site (neutrophils and macrophages) in order to phagocytose foreign substances, cell debris and microbes. Any damaged collagen in the wounded papillary dermis is then repaired through the action of fibroblasts, ultimately laying down scar tissue. Over long periods of time the tattoo ink particles can be found to gradually move to the deeper dermis (i.e., reticular dermis), which gives the tattoo a faded and blurred appearance. Importantly, after tattoo ink insertion associated pigment particles can be found to leave the skin via its vasculature and enter the lymphatic system (nodes) [3].”
#Lawal, Rohilla & Marston. Visualization of drug delivery via tattooing: effect of needle reciprocating frequency and fluid properties. 2022.
https://link.springer.com/article/10.1007/s12650-021-00816-5
Quote: “After the procedure, the body's immune system kicks into overdrive (from the thousands of micro injuries that just occurred) and responds by; inflammation which is immediately triggered by tissue phagocytes at the scene of injury. These cells release histamines that cause a transient increase in vasodilation and vascular permeability accompanied with the release of cytokines that signal the next phase; influx of monocytes through the blood vessels (aided by vasodilation). Monocytes become macrophages when they reach the site of injury, after which they either consume the deposited ink and traverse to the lymph nodes for excretion or remain in the dermis (a reason for the seemingly permanent nature of tattoos) (Petersen and Roth 2016).”
#Islam, P.S., Chang, C., Selmi, C. et al. Medical Complications of Tattoos: A Comprehensive Review. 2016.
https://link.springer.com/article/10.1007/s12016-016-8532-0
Quote: “With a fresh tattoo, the ink extends from the surface of the skin to the dermis. There is disruption of the epidermal basement membrane and some necrosis of the involved dermal and epidermal cells. Studies on fresh tattoos (using pigment-type ink) demonstrate phagocytosis of the pigment in the first 2 h by exudated polymorphonuclear leukocytes. Thereafter, no pigment granules are present in the leukocytes [18]. At about 24 h, pigment aggregates in cytoplasmic phagosomes in keratinocytes, macrophages, mast cells, and fibroblasts [19]. Langerhans cells may identify foreign antigens and transport them to the draining lymph nodes invoking a subsequent lymphocytic response. Due to needling
of the basement membrane, some of the dermal pigment may be extruded back through transepidermal elimination. At 1 month, transepidermal elimination is still occurring and pigment is found in keratinocytes, macrophages, and fibroblasts. Once the basement membrane has been restored, presumably no further transepidermal elimination occurs. Tattoo ink may be found in draining lymph nodes”
Experiments on mice suggest that tattoos stay because ink particles are taken up by one macrophage after the other. When a macrophage dies, it releases the particles inside. Then another macrophage comes along, clears away the cellular cadaver and eats up the ink particles. Since the ink particles are too big to get drained into the lymph nodes, they get stuck in there until another macrophage ingests them.
#Baranska et al. Unveiling skin macrophage dynamics explains both tattoo persistence and strenuous removal. 2018
https://rupress.org/jem/article-pdf/215/4/1115/1759956/jem_20171608.pdf
Quote: “Although the dermis lacked macrophages for approximately 1 wk after DT treatment and it took several more weeks for the incoming macrophages to scavenge the released cell-free tattoo pigments, no macroscopic modification of the tattoo occurred.
Before our study, the longevity of the undefined tattoo-pigment-laden cells found in the dermis was thought to be in the same order of that of a human adult, thereby accounting for long-term tattoo persistence (Fig. 10 B). Based on the present results, an alternative model for long-term tattoo persistence can be proposed. It takes into consideration the facts that the macrophages found in the dermis of adult mice are continuously replenished from circulating monocytes to compensate for the loss of dying macrophages and that most of the tattoo particles that are released from macrophages after DT treatment of CD64dtr mice remain in situ and are recaptured by incoming macrophages. According to the pigment capture–release–recapture model (Fig. 10 A), in physiological conditions, when tattoo-pigment-laden macrophages die during the course of adult life, neighboring macrophages recapture the released pigments and ensure in a dynamic manner the macroscopic stability and long-term persistence of tattoos. Note that, in contrast to dermal cDCs, dermal macrophages do not have the capacity to migrate to draining LNs under normal and inflammatory conditions (Tamoutounour et al., 2013), an essential property for insuring tattoo persistence. Whether the pigment capture–release–recapture model of tattoo persistence applies to humans remains to be determined. In the case of the melanophages found in the human dermis, it has been suggested that they persist for years through longevity rather than continual renewal (Bigley et al., 2011).”
– Lasers, UV light, wifi or x-rays are all the same thing: Electromagnetic radiation, photons that travel through space at the speed of light in the form of a wave. The more energetic they are, the higher their frequency and the more punch they carry.
#The EM spectrum. University of Tennessee, Knoxville. Retrieved August 2025
http://labman.phys.utk.edu/phys222core/modules/m6/The%20EM%20spectrum.html
Quote: “Visible light makes up just a small part of the full electromagnetic spectrum. Electromagnetic waves with shorter wavelengths and higher frequencies include ultraviolet light, X-rays, and gamma rays. Electromagnetic waves with longer wavelengths and lower frequencies include infrared light, microwaves, and radio and television waves.”
#Encyclopaedia Britannica. Electromagnetic Spectrum. Retrieved August 2025
#Gourzoulidis G, Tsilikas I, Serafetinides A et al. The Identification Of Occupational Exposure To Laser Radiation In Greece. e-Journal of Science & Technology. 2017
Quote: “Figure1. Most commonly used laser types over the optical spectrum; many wavelengths may be available from the same active medium.”
#McClements, D. Laser Wavelength: Wavelength Factors, How Does It Vary? Xometry. 2025
https://www.xometry.com/resources/sheet/laser-wavelength/
Quote: “The wavelength of a laser is its most fundamental characteristic, determining its properties, material interactions, and applications. The laser wavelength is usually measured in nanometers (nm), one nanometer being 10-9 meters. Laser wavelength is inversely proportional to frequency (units: Hz, kHz, MHz). Different laser technologies emit light at varied wavelengths, and the selection of wavelength depends on the specifics of the application and desired characteristics.
[...]
The wavelength of a laser refers to the spatial period of the electromagnetic wave it produces. It is the distance between consecutive peaks (or troughs) of the wave, which defines one characteristic of the emitted light.
In the analysis of laser light, the wavelength is the most fundamental property that determines the color or frequency of the laser light. Most lasers emit on a very narrow spectrum, i.e., they are monochromatic. Different emitter chemicals/mechanisms emit light at particular wavelengths related to their chemical and electromagnetic properties. The wavelength of emission has significant implications for the laser's behavior and interactions with materials, and, therefore, appropriate applications.
[...]
The most immediate and visually noticeable indication of the laser wavelength is the color of the emitted light, when in the visible range. Wavelengths correspond directly to color in the electromagnetic spectrum. Shorter wavelengths are associated with violet and blue colors (moving into invisible ultraviolet), while longer wavelengths are associated with red (trending into the invisible infrared).
The energy of individual photons in the laser beam is directly related to the wavelength. Shorter wavelengths correspond to higher energy, and longer wavelengths correspond to lower-energy photons. The wavelength of laser light determines how it interacts with target materials. All materials absorb, reflect, and transmit light at characteristic wavelengths.”
– Imagine your skin as jelly and your tattoo as crumbs of toast. If you shine a flashlight against it, most light passes right through the jelly – but the darker toast crumbs absorb more light and are clearly visible. Likewise, certain laser frequencies mostly pass through your skin without doing damage, while dark ink particles soak them up.
Depending on the colour of your tattoo, we need different lasers. Red ink reflects red light but absorbs green light – so you need a green laser. Black ink easily absorbs all types of light and is the easiest to remove.
There are different types of lasers used for tattoo removal. The standard in use today are so-called QS (quality-switched) lasers, which can output very short pulses of high intensity laser beams. Until a few years ago, nanosecond QS lasers were the state of the art: their pulses are as short as a few nanoseconds. Nowadays, the picosecond lasers are widely considered to be the gold standard, which output even shorter pulses (sub-nanosecond, i.e. picosecond), can remove tattoos even more efficiently and are equally as safe.
Regardless of pulse duration, all modern tattoo removal lasers operate on the same underlying principle: highly specific, high-energy laser beams with specific wavelengths are used to target specific pigments in the tattoo ink and destroy the ink particles.
Some laser wavelengths may interact with – and get partially absorbed by – skin components such as the skin pigment melanin (if e.g. the laser targets darker ink colors) and/or the hemoglobin found in blood vessels (if e.g. the laser targets red ink colors). In people with darker skin types, the higher density of melanin can increase the chance of unwanted side effects of laser tattoo removal, such as hyper- and hypopigmentation (darkened and/or lightened skin spots) when certain types of laser are used.
Depending on the color of the ink, different lasers have to be used for optimal removal of that color. Some colors are easier to remove than others: black tends to be the easiest to remove, i.e. most responsive to laser removal, while lighter colors such as green or white tend to be harder to remove.
Because they are so similar in their mechanism, in this video we generally consider the effects of both nano- and picosecond lasers, unless otherwise specified.
#Kono T, Chan HHL, Groff WF, Imagawa K, Hanai U, Akamatsu T. Prospective Comparison Study of 532/1064 nm Picosecond Laser vs 532/1064 nm Nanosecond Laser in the Treatment of Professional Tattoos in Asians. Laser Ther. 2020
https://pmc.ncbi.nlm.nih.gov/articles/PMC7447827/
Quote: “Background and Aims: Although, the pulse width should be shorter than the thermal relaxation time of the target, nanosecond laser pulses are not short enough for tattoo removal. Complications are common, such as hyper or hypopigmentation, textural changes, and scarring. Moreover, patients with darker skin types are at a higher risk of complications from tattoo removal using these lasers. Picosecond lasers were developed to overcome the limitation of nanosecond lasers. We did a comparison study of a 532/1064 nm picosecond laser vs a 532/1064 nm nanosecond laser to evaluate the clinical efficacy and complications of multi-color tattoos in Asians.
Materials and Methods: Eleven Asian patients with 37 professional tattoos were enrolled in the study. Each patient was treated with a 532/1064 nm nanosecond laser and a 532/1064 nm picosecond laser. The spot size that was used with each laser was 3 mm. Four treatments were performed, with four week intervals between each treatment. Patients were examined a week after the first treatment and 3 months after the last treatment.
Results and Conclusions: All patients tolerated the treatments well. The efficacy of the 1064 nm picosecond laser for black tattoos is significantly better than the other studied lasers. The efficacy of the 532 nm picosecond laser is significantly better than the other studied lasers for red tattoos. The efficacy of the 532 nm picosecond laser is significantly better than the 532 nm nanosecond laser and better than the 1064 nm picosecond laser for green tattoos. Mild to moderate post-inflammatory hyperpigmentation was observed in 35.1%, 24.3% 27.0%, and 21.6% of the tattoos treated with the 532 nm nanosecond laser, the 532 nm picosecond laser, the 1064 nm nanosecond laser, and the 1064 nm pico-second laser, respectively. Paradoxical darkening (5.4%) was observed equally with each type of laser. There was no scar formation in any of the tattoos treated. The 532/1064 nm picosecond laser is more effective than the 532/1064 nm nanosecond laser in the treatment of multi-color tattoos in Asians. The 532 nm picosecond laser is more effective than 1064 nm picosecond laser in every tattoo color, with the exception of black. Paradoxical darkening was observed, even the use of picosecond lasers.
[...]
The 532/1064 nm picosecond laser is more effective than the 532/1064 nm nanosecond laser in the treatment of multi-color tattoos. The 1064 nm picosecond laser is more effective than the other studied lasers in the treatment black ink. The 532 nm picosecond laser is more effective than 1064 nm picosecond laser in every color, exception for black ink.”
#Laux et al. A medical-toxicological view of tattooing. 2015.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(15)60215-X/fulltext
Quote: “Laser removal is less extreme and routinely preferred in absence of allergic reactions. The corresponding wavelength-induced thermophotolysis allows selective targeting of colourants without destroying the skin. The preferred three types of lasers are Q-switched versions of the ruby laser (λ=694 nm; effective against black, blue, and green), the Nd:YAG laser (λ=1064 nm and 532 nm; effective against black and dark blue or red orange and some yellows), and the alexandrite laser (λ=755 nm; effective against black, blue, and green).68,72”
#Kurniadi I, Tabri F, Madjid A, Anwar AI, Widita W. Laser tattoo removal: Fundamental principles and practical approach. Dermatol Ther. 2021
#Hohman MH, Ramsey ML. Laser Tattoo Removal. [Updated 2025 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK442007/
Quote: “With ruby, alexandrite, Nd:YAG, and frequency-doubled Nd:YAG (also known as potassium-titanyl-phosphate [KTP] because of the additional crystal used) lasers available for tattoo removal, selecting the most appropriate one for an individual patient's tattoo colors and skin pigmentation may be challenging. The alexandrite and ruby lasers emit deep, red-colored beams (755 nm and 694 nm, respectively), while the KTP laser is green (532 nm), and the Nd:YAG laser operates in the near infra-red range (1064 nm). As a general rule, tattoos are not treated effectively with lasers that produce light of the same color as the ink because that is the color reflected most efficiently by the pigment; for example, a ruby laser is liable to have little impact on a red tattoo, but treatment with a KTP laser would likely be successful. The ruby laser is best for blue, green, and purple pigments, the alexandrite for blue and green, the Nd:YAG for blue and green, and the KTP laser for red, yellow, brown, and orange. Because black pigment absorbs a broad spectrum of light wavelengths, the ruby, alexandrite, and 1064 nm Nd:YAG lasers can be effective for removing black tattoos, or even for tattoos that have undergone paradoxical darkening, although these tattoos may not clear completely even with a great many treatments (see Table. Type of Lasers for Tattoo Removal, Table).[20][21][22]
[...]
Type of Lasers for Tattoo Removal, Table. This table shows the types of lasers for tattoo removal, their wavelength, laser color, and pigments they are used to remove. Contributed by MH Hohman, MD, FACS, and S Jones, MD”
#Aljubran, B.A., Ross, K.E., Alexander, U. et al. Challenges in laser tattoo removal: the impact of titanium dioxide on photodegradation of yellow inks. Arch Toxicol 2025
https://link.springer.com/article/10.1007/s00204-025-03989-2
Quote: “As tattoos have grown increasingly popular, there has been an increase in their removal. This is commonly achieved using laser treatments. However, certain tattoo inks are resistant to removal using laser methods because of their composition. This includes the removal of yellow pigments and tattoo inks containing titanium dioxide (TiO2). This research examined a series of yellow pigments (PY14, PY74, PY65) and tattoo inks, pre- and post-irradiation, with a QS Nd:YAG laser irradiation at 532 nm. The pigments and products were analysed using a range of techniques, including EDX-SEM, DLS, XRD and GC-MS. Results of this study indicate that the presence of TiO2 alters the laser degradation process of the pigments studied, with observable changes to particle morphologies, particle size, and evolved volatile products. In addition, some of the degradation products were identified to be potentially harmful to the human body.”
#Pincelli G, Sena MM, Pavani C. Nd:YAG Laser Tattoo Removal in Individuals With Skin Phototypes IV-VI: A Case Series. J Lasers Med Sci. 2022
https://pmc.ncbi.nlm.nih.gov/articles/PMC10082917/
Quote: “Introduction: Although tattoos are ancient and very popular among young people, it is also a reason for regret, and many people today have a desire to remove them. Among the possibilities for this, laser removal is the most successful procedure with the highest degree of pigment removal and the lowest risk of complications.
Methods: This study was recorded on three patients with tattoos, and only the black pigments were removed. None of the patients involved had a history of skin allergies, skin cancer, and/or keloid formation. Case 1 had a professional tattoo removed in the right calf region in two sessions. Case 2 had an amateur tattoo that was removed on the scalp in three sessions. Finally, Case 3 had two professional tattoos, which were removed from the face in a total of eleven sessions. The following equipment was used: Spectra XT Q-Switched Nd:YAG 1064 nm with a pulse width of 5 ns; Pico Ultra 300 Nd:YAG 1064 nm with a pulse width of 300 ps; and SoftLight Q-Switched Nd:YAG 1064 nm with a pulse width of 17 ns.
Results: In general, satisfactory results were obtained, but hypopigmentation was present in Cases 1 and 3. This was probably due to sun exposure at the laser removal site, the short interval between the sessions, and/or higher radiant exposure combined with a smaller spot size, respectively.
Conclusion: To achieve a successful tattoo removal in the higher phototypes and reduce unwanted effects, the professionals must know the best parameters to be used, as well as the adequate foundation on the individual characteristics of each patient and the tattoos. Furthermore, patient compliance with the pre/post session care and a suitable interval between the laser sessions are essential to avoid undesirable complications.”
– But even with the right colour, tattoo removal lasers are still pretty powerful and still can leave horrible injuries, scars, or change your skin colour permanently.
Generally speaking, modern medical lasers are extremely safe in their applications in tattoo removal. When something goes wrong it is mostly either due to a rare allergic reaction in the patient, or user error by the person applying the laser removal treatment.
#Reiter, O., Atzmony, L., Akerman, L. et al. Picosecond lasers for tattoo removal: a systematic review. Lasers Med Sci 31, 1397–1405 (2016).
https://doi.org/10.1007/s10103-016-2001-0
Quote: “Given that the pigment particles in tattoos have a relaxation time of <10 ns, picosecond lasers would be expected to be more effective than nanosecond lasers in tattoo removal. To systematically review the evidence regarding the effectiveness and safety of picosecond lasers for tattoo removal, Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and reference lists were searched for relevant trials. [...] In the human trials, 69–100 % of tattoos showed over 70 % clearance of pigment after 1–10 laser treatments. Reported side effects included pain, hyperpigmentation and hypopigmentation, blister formation and transient erythema, edema, and pinpoint bleeding.”
#Hohman MH, Ramsey ML. Laser Tattoo Removal. [Updated 2025 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK442007/
Quote: “The most likely complication of laser tattoo removal is a requirement for more treatments than originally anticipated or unsatisfactory clearing of the tattoo, which may include residual pigment, a change in color or darkening, or a persistent outline of the artwork. Long-term or permanent skin changes may also occur, including alterations in texture and color. Hyperpigmentation is more common than hypopigmentation, although hypopigmentation is more likely to be permanent. Hyperpigmentation is treated with topical bleaching agents, such as 4% hydroquinone cream, while hypopigmentation may be treated with steroids to reduce the causative inflammation or with exposure to blue or ultraviolet light to stimulate melanin production.[37] Poor wound healing, such as blistering, infection, and scarring may occur, as can infection, although this is not common. If the settings employed are too aggressive, burning, skin sloughing, and scarring may result.”
#Khunger N, Molpariya A, Khunger A. Complications of Tattoos and Tattoo Removal: Stop and Think Before you ink. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411590/
Quote: “Pigments remaining in the skin may exhibit different chemical characteristics as compared to nonirradiated pigments again stimulating a reaction of the immune system. Some tattoo pigments containing metals could theoretically break down into toxic chemicals in the body when exposed to light. This has not yet been reported in vivo but has been shown in laboratory tests. It has also been shown that carcinogenic amines are generated by a laser-induced cleavage of azo dyes.[39] The complications of laser tattoo removal can be divided into immediate and delayed [Table 2].
[...]
Immediate complications
These include pain, blisters [Figure 4], crusting and pinpoint haemorrhage [Figure 5]. These are more common in darker skins, using a high fluence. Pain during the laser procedure can be reduced by application of topical anesthetic cream. One report suggests that application of the laser light through a microscope glass slide can reduce the pain and blistering.[40] If crusting occurs, topical emollient or topical antibiotic should be prescribed. The patient should be advised not to pick at the crusts as this can lead to pigmentary changes. Pinpoint haemorrhage subsides spontaneously. An acute allergic reaction in the form of urticarial lesion has been reported.[41]
[...]
Delayed complications
The most common complication is pigmentary changes, either hypopigmentation [Figure 6] or hyperpigmentation. These occur 4-6 weeks after laser treatment and most of them are transient. However, longer-lasting pigmentary alterations can occur, especially in darker or tanned skin.[42] Kirby et al. reported hypopigmentation in 8% and hyperpigmentation in 22% of patients with darker skins. Leukotrichia with permanent whitening of the eyelashes has been reported following laser tattoo removal of permanent eyeliner.[43]
[...]
Local allergic reactions, particularly to the red and yellow pigment can occur in the form of pruritic papules, nodules or scaly plaques. Rarely systemic reactions following laser treatment of allergic tattoos have been reported.[44] Photoallergic reactions can occur in the red or yellow ink. These allergic reactions may be early or delayed after several months or years following tattoo removal.[45] These allergic reactions should be treated with topical and intralesional corticosteroids.
Paradoxical darkening of tattoos can occur, particularly the light-coloured pink, tan or white-coloured tattoos, which are often used for permanent makeup.[46] This occurs due to reduction of titanium dioxide or iron oxide by the laser, turning the pigment black. Hence a small test area should be done first. When the tattoos turn black, they can be managd by further treatment with the Q-switched lasers. In removal of permanent makeup, it is sometimes wiser to treat with fractional CO2 laser or fractional Er:YAG laser to avoid paradoxical darkening.
It is sometimes difficult to remove the tattoo entirely, particularly the multicoloured professional tattoos and residual pigment can remain or there may be a ghost image. Textural changes can occur and these may be transient or permanent. Scarring can occur if a high fluence is used, particularly in dark or tanned skin, because the epidermal melanin absorbs most of the laser radiation [Figure 7]. In a large prospective study of laser tattoo removal, adverse effects were observed in only 6.2% of patients with hyperpigmentation being the commonest observed in 4.8%.[46]”
– So instead of shooting your skin with a continuous ray of death, modern tattoo removal lasers shoot an extremely brief pulse – a packet of electromagnetic energy that lasts about a few TRILLIONTH of a second.
There are different types of lasers used for tattoo removal. Most of the ones in use today are so-called QS (quality-switched) lasers, which can output very short pulses of high intensity laser beams. Until a few years ago, nanosecond QS lasers were the state of the art: their pulses were as short as a few nanoseconds. Nowadays, the gold-standard in laser tattoo removal are picosecond lasers, which output even shorter pulses (sub-nanosecond, i.e. picosecond).
Regardless of pulse duration, all modern tattoo removal lasers operate on the same underlying principle: highly specific, high-energy laser beams with specific wavelengths target specific pigments in the tattoo ink and destroy the ink particles. Depending on the color of the ink, different lasers are used.
#Ho SG, Goh CL. Laser tattoo removal: a clinical update. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411606/
Quote: “Picosecond lasers, with pulse duration of 10−12 seconds, are the newest lasers promising fast and efficacious tattoo removal. Ross et al. first compared the use of nanosecond and picosecond lasers for the treatment of black tattoos in human patients, all other parameters being equal, and reported tattoo removal to be more effective with the picosecond pulse duration. As the common tattoo pigment is around 40nm in diameter, with thermal relaxation times of around 1 ns, the shorter picosecond pulse duration can better target the tattoo pigment with increased photomechanical breakup of the pigment.[40]”
#Laux et al. A medical-toxicological view of tattooing. 2015.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(15)60215-X/fulltext
Quote: “Laser removal is less extreme and routinely preferred in absence of allergic reactions. The corresponding wavelength-induced thermophotolysis allows selective targeting of colourants without destroying the skin. The preferred three types of lasers are Q-switched versions of the ruby laser (λ=694 nm; effective against black, blue, and green), the Nd:YAG laser (λ=1064 nm and 532 nm; effective against black and dark blue or red orange and some yellows), and the alexandrite laser (λ=755 nm; effective against black, blue, and green).68,72”
#Kurniadi I, Tabri F, Madjid A, Anwar AI, Widita W. Laser tattoo removal: Fundamental principles and practical approach. Dermatol Ther. 2021
#Hohman MH, Ramsey ML. Laser Tattoo Removal. [Updated 2025 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK442007/
Quote: “With ruby, alexandrite, Nd:YAG, and frequency-doubled Nd:YAG (also known as potassium-titanyl-phosphate [KTP] because of the additional crystal used) lasers available for tattoo removal, selecting the most appropriate one for an individual patient's tattoo colors and skin pigmentation may be challenging. The alexandrite and ruby lasers emit deep, red-colored beams (755 nm and 694 nm, respectively), while the KTP laser is green (532 nm), and the Nd:YAG laser operates in the near infra-red range (1064 nm). As a general rule, tattoos are not treated effectively with lasers that produce light of the same color as the ink because that is the color reflected most efficiently by the pigment; for example, a ruby laser is liable to have little impact on a red tattoo, but treatment with a KTP laser would likely be successful. The ruby laser is best for blue, green, and purple pigments, the alexandrite for blue and green, the Nd:YAG for blue and green, and the KTP laser for red, yellow, brown, and orange. Because black pigment absorbs a broad spectrum of light wavelengths, the ruby, alexandrite, and 1064 nm Nd:YAG lasers can be effective for removing black tattoos, or even for tattoos that have undergone paradoxical darkening, although these tattoos may not clear completely even with a great many treatments (see Table. Type of Lasers for Tattoo Removal, Table).[20][21][22]
[...]
Type of Lasers for Tattoo Removal, Table. This table shows the types of lasers for tattoo removal, their wavelength, laser color, and pigments they are used to remove. Contributed by MH Hohman, MD, FACS, and S Jones, MD”
#Aljubran, B.A., Ross, K.E., Alexander, U. et al. Challenges in laser tattoo removal: the impact of titanium dioxide on photodegradation of yellow inks. Arch Toxicol 2025
https://link.springer.com/article/10.1007/s00204-025-03989-2
Quote: “As tattoos have grown increasingly popular, there has been an increase in their removal. This is commonly achieved using laser treatments. However, certain tattoo inks are resistant to removal using laser methods because of their composition. This includes the removal of yellow pigments and tattoo inks containing titanium dioxide (TiO2). This research examined a series of yellow pigments (PY14, PY74, PY65) and tattoo inks, pre- and post-irradiation, with a QS Nd:YAG laser irradiation at 532 nm. The pigments and products were analysed using a range of techniques, including EDX-SEM, DLS, XRD and GC-MS. Results of this study indicate that the presence of TiO2 alters the laser degradation process of the pigments studied, with observable changes to particle morphologies, particle size, and evolved volatile products. In addition, some of the degradation products were identified to be potentially harmful to the human body.”
– So short that the beam ends before the first photon even hits the skin!
Depending on the type of tattoo removal laser used and the specific settings, the distance from the source of the laser light to the skin surface can be variable, but is typically roughly 1-4 cm.
We have received this insight from an expert on laser tattoo removal: “The distance from the lens of the laser handpiece to the skin is approximately 10-40 mm.”
The speed of light in air is ca. 299,702,547 m/s:
v = c/n = (299792458 m/s) / 1.0003 = 299702547.23583 m/s
(v = velocity, c = speed of light in vacuum, n = refractive index of air)
For 1 cm travel through air, the photon travel time would then be ca. 33 picoseconds:
0.01 m/(299,702,547 m/s) = 3.3366416e-11 s
For commercial tattoo removal lasers, the pulse range varies widely depending on the type of laser, the brand and/or model, and the settings applied by the user. For commercial picosecond lasers, pulse durations used in tattoo removal typically range from 300-750 ps. The shortest pulse length for tattoo removal advertised by commercial picosecond lasers is 8 ps (https://lightsenselaser.com/our-technology/).
For a pulse length of 8 ps, the travel distance of a photon would be ca. 2.4 mm:
299702547 m/s * 8e-12 s = 0.0024 m
During an 8 ps laser pulse, the photons would therefore travel only 2.4 mm away from the light source before the pulse ends. But they need to travel at least 1 cm before they hit the skin, meaning that the pulse ends before the first photon has reached the skin surface.
#Encyclopaedia Britannica. Speed of light. Retrieved September 2025
https://www.britannica.com/science/speed-of-light
Quote: “speed of light, speed at which light waves propagate through different materials. In particular, the value for the speed of light in a vacuum is now defined as exactly 299,792,458 metres per second.”
#Refractive Index Info. Retrieved September 2025
https://refractiveindex.info/?shelf=other&book=air&page=Ciddor
Quote: “In terms of its optical properties, air has a refractive index very close to 1 (approximately 1.0003 at sea level under standard conditions), which varies slightly with temperature, humidity, and pressure.”
#LightSense Technologies. How it Works - Is LightSense™ a pico laser? Retrieved September 2025.
https://lightsenselaser.com/our-technology/
Quote: “The LightSense™ laser system is a type of pico laser. It has an extremely short pulse width of eight picoseconds, 89x shorter when compared to the average pico laser.”
– The pulse of high energy photons hits your arm nearly at the speed of light, shooting through the dead layers of the skin, passing into the dermis.
The outermost layer of the skin (Stratum corneum, part of the epidermis) is composed of dead skin cells. During the process of tattooing, ink particles are deposited in a deeper skin layer (dermis).
#Pouillot A, Dayan N, Polla AS, Polla LL, Polla BS. The stratum corneum: a double paradox. J Cosmet Dermatol. 2008
https://pubmed.ncbi.nlm.nih.gov/18482020/
Quote: “The stratum corneum (SC) (i.e., the outermost layer of human skin) is a complex and paradoxical tissue composed of corneocytes and a matrix of intercellular lipids playing an essential role as the skin's protective barrier. The first paradox of SC is its dual nature. It is composed of nondividing (dead) cells embedded in a metabolically active (live) environment whose function is to protect the epidermis and to maintain its integrity.”
#Grant et al. Tattoo ink nanoparticles in skin tissue and fibroblasts. 2015.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4464189/pdf/Beilstein_J_Nanotechnol-06-1183.pdf
Quote: “Thus, the needle penetrates the skin through the epidermis and into the papillary layer of the dermis, where the ink particles accumulate. As with any type of trauma to the dermis, the first response of the body is to stop the resultant bleeding to form a clot. Then the skin tissue swells (edema) followed by a migration of immune system cells to the wound site (neutrophils and macrophages) in order to phagocytose foreign substances, cell debris and microbes. Any damaged collagen in the wounded papillary dermis is then repaired through the action of fibroblasts, ultimately laying down scar tissue. Over long periods of time the tattoo ink particles can be found to gradually move to the deeper dermis (i.e., reticular dermis), which gives the tattoo a faded and blurred appearance. Importantly, after tattoo ink insertion associated pigment particles can be found to leave the skin via its vasculature and enter the lymphatic system (nodes) [3].”
– Most cells are like jelly to the laser and don’t absorb much energy, escaping its deadly power unharmed.
Modern, well-calibrated tattoo removal lasers are able to highly specifically target the ink particles due to their extremely specific wavelength, while minimizing damage to the surrounding tissue. They should generally not cause permanent damage to skin tissue or hair follicles. Some people report temporary hair thinning at the site of the tattoo removal, but most often this returns to normal after some time. Some surface hair might get singed during the procedure if the area was not shaved before.
#Barua S. Laser-tissue interaction in tattoo removal by q-switched lasers. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411594/
Quote: “Anderson and Parrish, in their landmark papers on skin optics,[7,8,9] propounded the theory of selective photothermolysis. This theory postulates that light of a wavelength that is absorbed by a target chromophore will selectively damage or destroy that chromophore if the fluence is sufficiently high and the pulse duration is less than or equal to the thermal relaxation time (TRT) of that chromophore. It follows, therefore, that if the laser pulse duration is less than the TRT of the target chromophore, heat diffusion does not take place and the damage is selectively confined to the target without any collateral injury to the surrounding tissues.”
– The flood of photons moves on and reaches the mountain range of ink embedded deep in the prison of your flesh and cells.
Only a nanosecond, a billionth of a second, has passed but now things escalate rapidly.
The typical pulse duration of a commercial tattoo removal laser is 300-900 picoseconds, i.e. 0.3-0.9 nanoseconds. The frequency of laser pulses is between 1-10 Hz (1-10 pulses per second), so the gap between pulses is on the order of magnitude of hundreds of milliseconds. We are focussing on the timespan between the first photons hitting the ink particles and the end of the first laser pulse (rounded up to 1 nanosecond).
#Kim JH, Jung SE, Park YH. Efficacy of a laser with a pulse duration of 300 ps in skin rejuvenation and treatment of pigmentation disorders in Asians: a series of four cases. J Cosmet Laser Ther. 2021
https://www.tandfonline.com/doi/full/10.1080/14764172.2021.2016846
Quote: “Initially, picosecond lasers were used for tattoo removal to provide better treatment results and reduce side effects compared to nanosecond lasers but, recently, they have also been effectively used to treat various pigment disorders, acne scars, and wrinkles (Citation8).
Currently, picosecond lasers commonly used in dermatology have a pulse duration of 300–900 ps (Citation9).”
#Pincelli G, Sena MM, Pavani C. Nd:YAG Laser Tattoo Removal in Individuals With Skin Phototypes IV-VI: A Case Series. J Lasers Med Sci. 2022
#Park KC, Park ES, Nam SM, Shin JS. The Utility of Picosecond Nd:YAG Laser for Tattoo Removal. Medical Lasers 2021
https://doi.org/10.25289/ML.2021.10.1.31
Quote: “Single procedure with one pass were performed using a spot size of from 4 mm, fluence of 2.5 to 4.8 J/cm2, repetition rate of 6 to 10 Hz.”
– As the photons hit the black ink on a molecular level, they smash into electrons and are absorbed and annihilated – transferring all of their energy into them. This sudden influx of energy almost instantly turns into a massive amount of heat that has nowhere to go.
#Deep Analysis of the Principle of Laser Heating Technology. Lemon Photonics. Retrieved August 2025
https://en.lemonphotonics.com/articledetail/66.html
Quote: “The essence of laser heating is the energy conversion caused by the interaction between light energy and matter. When a high-energy laser beam irradiates the surface of an object, its unique monochromaticity (single wavelength) and high coherence make the photon energy highly concentrated, far exceeding that of ordinary light sources. The electrons on the surface of an object transition to a high-energy state by absorbing the energy of photons, and then transfer the energy to the lattice atoms through collisions, causing the atoms to vibrate violently (i.e., heat energy is generated). This process is manifested microscopically as an increase in material temperature and macroscopically as a controllable heating effect.”
#Kurniadi I, Tabri F, Madjid A, Anwar AI, Widita W. Laser tattoo removal: Fundamental principles and practical approach. Dermatol Ther. 2021
Quote: “The fundamental principle in tattoo removal using laser is the concept of selective photothermolysis. Since first introduced by Anderson and Parrish, it has become the basic rationale to target specific substances in the skin, such as melanin, pigment, water, and oxyhemoglobin, using laser while preserving the surrounding area. (16, 17) These molecules are able to absorb laser of a certain wavelength and are called chromophores; different chromophores have different optimal wavelength absorption. When a chromophore absorbs photon of a certain wavelength, chemical reaction will occur and produce heat that propagate to the surrounding tissue. Thermal relaxation time (TRT) of a chromophore is defined as the required time to for a chromophore to lose 50% of the heat it experienced following laser exposure. Selective photothermolysis theory states that when a chromophore is heated with a duration of less than its TRT, chromophore destruction without damage to the surrounding environment will occur. (16) The bigger the size of chromophore, the longer is the TRT, and vice versa. Practically, the duration of TRT of a chromophore is equivalent to the square of the chromophore diameter in millimeter. For example, the TRT of a tattoo particle with a diameter of 0.1 µm (10-4 mm) equals to 10 ns (10-8 s). (9) Besides thermal effect, photon absorption by chromophores also results in pressure force and is the basis for the inertial confinement time (ICT) concept which refers to the time required by pressure wave to traverse a target object. Mathematically, ICT is calculated by the formula d/va, where d is diameter of the target and va is the velocity of sound in the tissue (103 m/s). For example, the ICT for a tattoo particle with a diameter of 0.1 µm (10-7 m) is approximately 10-10 s or 100 ps. Similar to TRT, when a particle is hit by a certain amount of energy with duration of less than its ICT, mechanical stress capable of destroying the particle is generated (photoacoustic effect).(9)”
– The ink particles burn up to a seething hot 600 degrees, hot enough to make iron glow red hot.
It is very hard to measure exact temperatures in ink particles, and the temperature depends on the type of laser used, the laser settings (e.g. how much energy the laser beam transmits per surface area), and the color of the ink. There are some estimates by experts, and some large ranges of possible temperatures published. What is clear is that the surface temperature reached by the laser-treated ink particles is at several hundred degrees celsius, i.e. way above the boiling point of water. This is also evidenced by the formation of so-called “cavitation bubbles” during lasering: little pockets filled with water vapor from the surrounding tissue.
We also received this insight from an expert on laser tattoo removal: “In clinical practice, with picosecond pulses (e.g., 300–750 ps, wavelengths well absorbed by black ink, and fluences of around a few J/cm²), it is estimated that the particle surface undergoes an instantaneous temperature rise of approximately 200–600 °C, but under higher-end conditions (black ink, high fluence, particle aggregation, and strong thermal/stress confinement), temperatures in the vicinity of ~800 °C are theoretically possible.”
#Wenzel MS, MD. Current Concepts in Laser Tattoo Removal. 2010
Quote: “If treated properly, particles will reach very high absolute temperatures of several hundred degrees Celsius.”
#Ahn KJ, Zheng Z, Kwon TR, Kim BJ, Lee HS, Cho SB. Pattern analysis of laser-tattoo interactions for picosecond- and nanosecond-domain 1,064-nm neodymium-doped yttrium-aluminum-garnet lasers in tissue-mimicking phantom. Sci Rep. 2017
https://pmc.ncbi.nlm.nih.gov/articles/PMC5431496/
Quote: “The maximum temperature inside irradiated tattoo ink particles is reportedly below the melting point of graphite, although sufficiently higher than the boiling point of water5.”
– Overwhelmed by the sudden heat the ink particles expand rapidly and are mechanically stressed to the max, violently ripping and fracturing, almost exploding.
The mountain range cracks into millions of seething hot pieces and a bit of hot ink dust. Which would not be that bad if this was not going on inside your skin.
#Kasai K. Picosecond Laser Treatment for Tattoos and Benign Cutaneous Pigmented Lesions (Secondary publication). Laser Ther. 2017
https://pmc.ncbi.nlm.nih.gov/articles/PMC5801452/
Quote: “Theoretical background of picosecond lasers
Thermal lock-in (Thermal relaxation theory)
The thermal relaxation theory is based on the following proven phenomenon. If a certain structure is heated to a certain temperature, heat escapes to the surrounding tissue through heat conduction and if the heating takes place over a longer period, heat escapes while the structure is being heated and thus the temperature rise of the target structure is limited. Such a condition is called heat diffusion (Fig. 1 (a)). However if the structure is heated in a very short exposure time, the temperature rises quickly since there is no time for the heat to diffuse. This condition is called thermal lock-in (Fig. 1 (b)) 14, 15). Once thermal lock-in is achieved selective thermal destruction of the structure becomes possible. Whether or not thermal lock-in is achieved depends on the temporal threshold of the structure which is called the coefficient of thermal relaxation, or more simply, the thermal relaxation time (TRT), and the TRT depends on the absorption coefficient and heat diffusion coefficient of the structure.
[...]
Stress lock-in (Stress relaxation time theory):
In tattoo removal using the ns-domain Q switched lasers, it is argued that the pulse duration of the laser is shorter than the thermal relaxation time of the tattoo pigments and thus thermal lock-in is achieved. However at the same time, another important phenomenon called stress lock-in must be taken into consideration.
Stress relaxation can be explained simply as follows. When a certain particle is heated, thermal expansion of the particle occurs. The expansion diffuses to the surrounding tissue as vibration which is called stress diffusion (Fig. 2 (a)). When a particle is heated within an extremely short period of time, the stress generated within the particle has not enough time to diffuse and stress lock-in is achieved, 14, 15) and if the generated stress is high enough, fracture of the particle occurs. This is analogous to the thermal lock-in and extreme temperature rise in the thermal relaxation theory. The temporal threshold of the particle for stress lock-in to occur, the stress relaxation time (SRT), for tattoo pigments is thought to be slightly shorter than 1 ns. Therefore in tattoo removal using ns-domain Q-switched lasers, stress lock-in is not achieved since the pulse width of the lasers is longer than the stress relaxation time of the tattoo pigments. However when a ps-laser is used which can defeat the SRT, stress lock-in is achieved.
[...]
The different reactions comparing a ps-laser to an ns-laser can be summed up as follows. When an ns-domain Q-switched laser is used, the major reaction which takes place is photothermolysis through a photothermal reaction, with a very small photomechanical effect. However when a ps-laser is used, stress lock-in occurs and the major reaction involves the photoacoustic destruction of the particle, with a minor photothermal component. Therefore more efficient and effective destruction of the particle becomes possible. Also, since heat generation through light absorbance decreases, color dependence for the reactions decreases as well. It is anticipated that the less heat generation will lead to less heat induced complications such as discoloration of the tattoo. Such tendencies have already been seen in some clinical settings but have yet to be confirmed comprehensively.”
#Kroma-Szal, A., Pawlaczyk, M, Urbańska, M et al. Medical Applications of Picosecond Lasers for Removal of Non-Tattoo Skin Lesions—A Comprehensive Review. Appl. Sci. 2025
https://www.mdpi.com/2076-3417/15/9/4719
Quote: “A picosecond laser interacts with various tissues through two primary mechanisms: photo-thermo-mechanical disruption (PTMD) and laser-induced optical breakdown (LIOB) [7]. The former relates to non-fractionated laser beams and is based on the principle that ultrafast temperature changes, which are induced by the picosecond pulses, generate intense acoustic shock waves within the targeted chromophores, creating tensile stress which exceeds the rupture threshold of a chromophore [2]. A significant photomechanical interaction occurs when the duration of the pulse is shorter than stress relaxation time [7].
This photomechanical (photoacoustic) effect is the main method of fragmenting subdermal ink particles (tattoo) and cellular melanosomes using picosecond laser irradiation, facilitating their clearance by macrophages and other phagocytic cells [2].”
#Barua S. Laser-tissue interaction in tattoo removal by q-switched lasers. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411594/
Quote: “QS lasers work on the principle of selective photothermolysis and also produce an additional photoacoustic effect, producing shock waves that cause explosion of the target.[8,10,11] Very high energy to the tune of 300 MW is delivered in a very short period of time (5-100 ns), which leads to rapid thermal expansion. This produces shock waves that rupture the targeted ink particles.[12,13]
#Tjipta A, Ramadhan H, Lubis RA. Immune Response in Laser Tattoo Removal: A Systematic Review. J Lasers Med Sci. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10843227/
Quote: “Conversely, in the context of tattoo removal utilizing Q-switched lasers, the laser beam is assimilated by the pigment particles present within the dermis. Q-switched lasers are characterized by their short pulse duration and high intensities, which result in the rapid heating of pigment particles. The application of this technique has the potential to induce shock waves, thus causing fragmentation of the pigment particles within the dermal layer.”
#Kurniadi I, Tabri F, Madjid A, Anwar AI, Widita W. Laser tattoo removal: Fundamental principles and practical approach. Dermatol Ther. 2021
Quote: “The fundamental principle in tattoo removal using laser is the concept of selective photothermolysis. Since first introduced by Anderson and Parrish, it has become the basic rationale to target specific substances in the skin, such as melanin, pigment, water, and oxyhemoglobin, using laser while preserving the surrounding area. (16, 17) These molecules are able to absorb laser of a certain wavelength and are called chromophores; different chromophores have different optimal wavelength absorption. When a chromophore absorbs photon of a certain wavelength, chemical reaction will occur and produce heat that propagate to the surrounding tissue. Thermal relaxation time (TRT) of a chromophore is defined as the required time to for a chromophore to lose 50% of the heat it experienced following laser exposure. Selective photothermolysis theory states that when a chromophore is heated with a duration of less than its TRT, chromophore destruction without damage to the surrounding environment will occur. (16) The bigger the size of chromophore, the longer is the TRT, and vice versa. Practically, the duration of TRT of a chromophore is equivalent to the square of the chromophore diameter in millimeter. For example, the TRT of a tattoo particle with a diameter of 0.1 µm (10-4 mm) equals to 10 ns (10-8 s). (9) Besides thermal effect, photon absorption by chromophores also results in pressure force and is the basis for the inertial confinement time (ICT) concept which refers to the time required by pressure wave to traverse a target object. Mathematically, ICT is calculated by the formula d/va, where d is diameter of the target and va is the velocity of sound in the tissue (103 m/s). For example, the ICT for a tattoo particle with a diameter of 0.1 µm (10-7 m) is approximately 10-10 s or 100 ps. Similar to TRT, when a particle is hit by a certain amount of energy with duration of less than its ICT, mechanical stress capable of destroying the particle is generated (photoacoustic effect).(9)”
– Water in your tissue and inside your cells instantly vaporizes and expands quickly. Ripping cells apart and growing into gigantic caves of hot steam bubbles inside your skin. This sudden expansion creates a shockwave that hits tissue nearby, causing more mayhem and damage.
#Barua S. Laser-tissue interaction in tattoo removal by q-switched lasers. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411594/
Quote: “QS lasers work on the principle of selective photothermolysis and also produce an additional photoacoustic effect, producing shock waves that cause explosion of the target.[8,10,11] Very high energy to the tune of 300 MW is delivered in a very short period of time (5-100 ns), which leads to rapid thermal expansion. This produces shock waves that rupture the targeted ink particles.[12,13]
[...]
Laser-tissue interaction produces intercellular steam and vacuole formation within the target pigment that cause a scattering of visible light, leading to immediate whitening.”
#Tjipta A, Ramadhan H, Lubis RA. Immune Response in Laser Tattoo Removal: A Systematic Review. J Lasers Med Sci. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10843227/
Quote: “Conversely, in the context of tattoo removal utilizing Q-switched lasers, the laser beam is assimilated by the pigment particles present within the dermis. Q-switched lasers are characterized by their short pulse duration and high intensities, which result in the rapid heating of pigment particles. The application of this technique has the potential to induce shock waves, thus causing fragmentation of the pigment particles within the dermal layer.”
#Baleisis J, Rudys R. Comprehensive examination of tattoo removal using a 150 ps Nd:YAG laser in a porcine model. Sci Rep. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10421900/
Quote: “In recent years, picosecond (ps) lasers have emerged as a more promising option for tattoo removal, as they have been shown to be more effective in terms of tattoo clearance and pain management in both preclinical10 and clinical studies11.
This tattoo removal technique is based on the photoacoustic effect, which is characterized by the rapid thermal expansion of targeted tissue following fragmentation and the release of mechanical supersonic or acoustic waves, resulting in the destruction of surrounding tissue12. The resulting fragmentation of pigments into smaller fragments allows for their phagocytosis by macrophages and subsequent removal via the lymphatic system13, leading to tattoo lightening14.”
#Kurniadi I, Tabri F, Madjid A, Anwar AI, Widita W. Laser tattoo removal: Fundamental principles and practical approach. Dermatol Ther. 2021
Quote: “The fundamental principle in tattoo removal using laser is the concept of selective photothermolysis. Since first introduced by Anderson and Parrish, it has become the basic rationale to target specific substances in the skin, such as melanin, pigment, water, and oxyhemoglobin, using laser while preserving the surrounding area. (16, 17) These molecules are able to absorb laser of a certain wavelength and are called chromophores; different chromophores have different optimal wavelength absorption. When a chromophore absorbs photon of a certain wavelength, chemical reaction will occur and produce heat that propagate to the surrounding tissue. Thermal relaxation time (TRT) of a chromophore is defined as the required time to for a chromophore to lose 50% of the heat it experienced following laser exposure. Selective photothermolysis theory states that when a chromophore is heated with a duration of less than its TRT, chromophore destruction without damage to the surrounding environment will occur. (16) The bigger the size of chromophore, the longer is the TRT, and vice versa. Practically, the duration of TRT of a chromophore is equivalent to the square of the chromophore diameter in millimeter. For example, the TRT of a tattoo particle with a diameter of 0.1 µm (10-4 mm) equals to 10 ns (10-8 s). (9) Besides thermal effect, photon absorption by chromophores also results in pressure force and is the basis for the inertial confinement time (ICT) concept which refers to the time required by pressure wave to traverse a target object. Mathematically, ICT is calculated by the formula d/va, where d is diameter of the target and va is the velocity of sound in the tissue (103 m/s). For example, the ICT for a tattoo particle with a diameter of 0.1 µm (10-7 m) is approximately 10-10 s or 100 ps. Similar to TRT, when a particle is hit by a certain amount of energy with duration of less than its ICT, mechanical stress capable of destroying the particle is generated (photoacoustic effect).(9)”
#Ahn KJ, Zheng Z, Kwon TR, Kim BJ, Lee HS, Cho SB. Pattern analysis of laser-tattoo interactions for picosecond- and nanosecond-domain 1,064-nm neodymium-doped yttrium-aluminum-garnet lasers in tissue-mimicking phantom. Sci Rep. 2017
– Your cells that were keeping the tattoo in place a moment ago are having a really bad time. If they had kept tattoo particles safely stowed inside of them they are cooked or ripped apart. The cells that surrounded the ink mountains are gravely wounded or burned alive by the sudden heat or steam. A few tiny blood vessels in the area are ripped apart violently.
Thousands of your cells are dead or hurt.
The destruction of ink particles using medical lasers is known to result in the destruction of macrophages holding those particles, and generalized “tissue damage” as a result of the physical shockwave, which is highly localized around the ink particles, i.e. it only affects a tiny area around the targeted particles. There is also some limited evidence that, depending on the type of lasers used (esp. its wavelength), some damage might occur in small blood vessels called capillaries. This might contribute to some of the redness and irritation felt around the laser-treated area for those types of lasers. But even in the absence of a laser-specific interaction with blood vessels, the mechanical disruption of the ink particles has the potential to damage miniscule blood vessels in the immediate surroundings.
#Pazos et al. Tattoo Inks for Optical Biosensing in Interstitial Fluid. 2021.
https://onlinelibrary.wiley.com/doi/full/10.1002/adhm.202101238
Quote: “Lasers heat the particle and before the particle distributes the heat around its surface, the laser repeats the pulse, and the particle deforms and breaks into smaller particles. Lasers also lyse the macrophages.[44,46]
#Baleisis J, Rudys R. Comprehensive examination of tattoo removal using a 150 ps Nd:YAG laser in a porcine model. Sci Rep. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10421900/
Quote: “In recent years, picosecond (ps) lasers have emerged as a more promising option for tattoo removal, as they have been shown to be more effective in terms of tattoo clearance and pain management in both preclinical10 and clinical studies11.
This tattoo removal technique is based on the photoacoustic effect, which is characterized by the rapid thermal expansion of targeted tissue following fragmentation and the release of mechanical supersonic or acoustic waves, resulting in the destruction of surrounding tissue12.”
#M. J. Murphy. Q‐switched 532‐nm laser energy causes significant vascular damage in the capillary plexus: how does this affect laser tattoo removal?, British Journal of Dermatology, 2018
Quote: “Tattoos can be effectively removed using Q‐switched and picosecond lasers at four wavelengths: 1064, 755, 694 and 532 nm.1,2,3,4 However, there are two particular problems with the 532‐nm line. Firstly, it is well absorbed by the melanin in the epidermis, because of its relatively high absorption coefficient,5 (μa_mel = 56 cm−1 for typical white skin). Secondly, 532 nm is also strongly absorbed in the oxyhaemoglobin located in the capillary plexus5 (μa_HbO = 260 cm−1).
In this small study, I compared the effects of Q‐switched pulses using all four of the above wavelengths on nontattooed skin. In particular, the effects of absorption in the blood layer was studied.
[...]
Only the 532nm spots show any obvious difference, with significantly more vascular damage occurring in the uncompressed skin regions. This is due to the relatively low absorption coefficients for 1064, 755 and 694nm compared with 532nm in blood 5. This indicates that much of the incident 532nm laser energy is absorbed by the blood layer leaving significantly less energy available to deeper levels, where large amounts of tattoo ink may be located1,2,7,8. The use of 532nm is commonplace in laser tattoo removal. The cumulative absorption of this wavelength in both melanin and blood reduces the total amount of energy which can reach the reticular dermis, while also mechanically damaging melanin granules and capillary vessels 2,7,8.”
– And then the next laser pulse hits again, and again, moving over the tattoo like an orbital bombardment.
Typical modern tattoo removal lasers operate at a frequency of 1-10 Hz, i.e. 1-10 pulses per second.
#Pincelli G, Sena MM, Pavani C. Nd:YAG Laser Tattoo Removal in Individuals With Skin Phototypes IV-VI: A Case Series. J Lasers Med Sci. 2022
#Park KC, Park ES, Nam SM, Shin JS. The Utility of Picosecond Nd:YAG Laser for Tattoo Removal. Medical Lasers 2021
https://doi.org/10.25289/ML.2021.10.1.31
Quote: “Single procedure with one pass were performed using a spot size of from 4 mm, fluence of 2.5 to 4.8 J/cm2, repetition rate of 6 to 10 Hz.”
– From your perspective all of this is happening so fast that you only notice one thing: A sharp pain like being electrocuted, a smell like burnt hair and most disturbingly – a loud crack.
#Khunger N, Molpariya A, Khunger A. Complications of Tattoos and Tattoo Removal: Stop and Think Before you ink. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411590/
Quote: “Immediate complications
These include pain, blisters [Figure 4], crusting and pinpoint haemorrhage [Figure 5]. These are more common in darker skins, using a high fluence. Pain during the laser procedure can be reduced by application of topical anesthetic cream. One report suggests that application of the laser light through a microscope glass slide can reduce the pain and blistering.[40] If crusting occurs, topical emollient or topical antibiotic should be prescribed. The patient should be advised not to pick at the crusts as this can lead to pigmentary changes. Pinpoint haemorrhage subsides spontaneously. An acute allergic reaction in the form of urticarial lesion has been reported.[41]
#Reiter, O., Atzmony, L., Akerman, L. et al. Picosecond lasers for tattoo removal: a systematic review. Lasers Med Sci 31, 1397–1405 (2016).
https://doi.org/10.1007/s10103-016-2001-0
Quote: “Given that the pigment particles in tattoos have a relaxation time of <10 ns, picosecond lasers would be expected to be more effective than nanosecond lasers in tattoo removal. To systematically review the evidence regarding the effectiveness and safety of picosecond lasers for tattoo removal, Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and reference lists were searched for relevant trials. [...] In the human trials, 69–100 % of tattoos showed over 70 % clearance of pigment after 1–10 laser treatments. Reported side effects included pain, hyperpigmentation and hypopigmentation, blister formation and transient erythema, edema, and pinpoint bleeding.”
Laser tattoo removal does produce a distinct odor that people often describe as similar to burning hair or flesh. When used correctly, modern tattoo removal procedures generally do not damage much surface hair, because it is recommended to shave it off before laser treatment. It is possible that the smell originates from the ink particles breaking down, and/or small amounts of remaining surface hair might get burned depending on the laser settings and the lack of shaving.
#LaserTat. Tattoo Removal Myths: Debunking Common Misconceptions. 2024
https://www.lasertat.com.au/blog/2024/3/19/tattoo-removal-myths-debunking-common-misconceptions
Quote: “Some clients also report experiencing a "burning" taste or smell during treatment. This is not caused by the skin burning but is instead a common side effect of the tattoo ink being broken down by the laser. As the ink particles are targeted, shattered, and then released into the body they may produce a distinct odour or taste, which clients may notice during the procedure.”
#Removery. Should I Shave Before Tattoo Removal? 2024
https://removery.com/blog/should-i-shave-before-tattoo-removal/
Quote: “In general you should shave before your tattoo removal so that the area for your removal is free of any obstruction.
Shaving also prevents the smell of burning hair during your laser session and any damage that could be done to your hair follicles.”
A sound is sometimes heard during laser tattoo removal - often described as a “crack” or “pop”. There are different hypotheses as to where this sound comes from. Some sources state that it is due to the photoacoustic effect breaking up or shattering the ink particles. Other sources state that it is from the laser interaction with the air between the light sources and the skin, creating rapid changes in air pressure. This mostly depends on the settings of the laser and the distance of the laser from the skin.
In any case, whether or not a sound is heard or how loud it is has no relationship to how effective the laser removal is.
#’Lasers in Skin’ Podcast. Laser Tattoo Removal - 'Mythconceptions'. 2025
Quote: “The idea that a cracking sound during treatment indicates effective tattoo removal is incorrect. This sound can occur when the laser is used improperly, leading to unnecessary skin damage.”
#Murphy M. Chasing the ‘crack’ in laser tattoo treatments! Is this right? 2021
https://mikemurphyblog.com/2021/07/21/chasing-the-crack-in-laser-tattoo-treatments-is-this-right/
Quote: “The ‘cracking’ sound is now clearly heard – even though there is no ink to absorb the energy! At such fluences there is enough concentrated energy (and power density) to interact with the oxygen in the air. If enough energy is output, ozone can be generated by the laser energy.
This also generates a loud cracking sound due to the extreme and rapid pressure changes in the air.”
#Barua S. Laser-tissue interaction in tattoo removal by q-switched lasers. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411594/
Quote: “An audible popping sound is heard during the laser procedure due to the photoacoustic effect.[15,16]”
– Where the laser hits your tattoo instantly turns white – which is called frosting and is the bubbles of hot gas expanding under your skin.
The tissue turning white is a direct result of the ink particles and surrounding tissue being affected by the laser. It is also the reason for why immediate additional passes with the laser would be ineffective: the tissue is now white-ish, and thus reflects and/or scatters much of the laser light, rendering the treatment inefficient.
#Barua S. Laser-tissue interaction in tattoo removal by q-switched lasers. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411594/
Quote: “Laser-tissue interaction produces intercellular steam and vacuole formation within the target pigment that cause a scattering of visible light, leading to immediate whitening.”
#Biesman BS, O'Neil MP, Costner C. Rapid, high-fluence multi-pass q-switched laser treatment of tattoos with a transparent perfluorodecalin-infused patch: A pilot study. Lasers Surg Med. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC5042086/
Quote: “When a tattoo is exposed to the high optical energy of a laser pulse, stress waves, and cavitation bubbles are formed 11. This effect is observed clinically as whitening or frosting over the tattoo. The apparent white layer is composed of microscopic bubbles formed nearly instantaneously as energy absorbed by the ink particles is transferred to surrounding tissue. The white layer is highly optically scattering and thus effectively opaque. Further laser passes are ineffective because light can no longer penetrate sufficiently to interact with the pigment.”
– To ease the pain the area is often cooled with a stream of cold air for a moment, before the laser moves on again.
#Hohman MH, Ramsey ML. Laser Tattoo Removal. [Updated 2025 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK442007/
Quote: “Cooling with cold air blown across the tattoo or periodic application of cold packs to the treated area will reduce patient discomfort and swelling.”
#Jung S, Yoo KH, Na S, Kim J. Efficacy of a new cryotherapy device on pain relief during the laser tattoo removal. Medical Lasers 2022
https://doi.org/10.25289/ML.2022.11.3.173
Quote: “Cooling therapy is therapeutic modality to address the pain relief. It is used for alleviating pain on specific area through topical application such as ice pack or for broader range pain relief through non-topical application such as cold bath, cold massage, refrigerant sprayer, and cold water perfusion.4”
– The cooked and ripped remains of cells float in a mix of hot ink and water vapor that are cooling down.
When being targeted by a laser pulse, the ink particles get heated up rapidly (photothermal effect) and then break into smaller fragments (photochemical and photoacoustic effect). In this process, the thermal energy is converted into mechanical energy as it fragments the particle, meaning that the particles get destroyed and cool down at the same time. Depending on the type of laser used and its settings, the fragmentation of the ink particles is more caused by the photothermal effect, or more by the photoacoustic effect.
#Khunger N, Molpariya A, Khunger A. Complications of Tattoos and Tattoo Removal: Stop and Think Before you ink. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411590/
Quote: “On delivery of the laser in the skin, the energy that is absorbed by the pigment is converted to heat, which is the photothermal effect. There is breakage of chemical bonds inside the pigment, which is the photochemical effects. There is a mechanical destruction of the pigments due to photoacoustic effects. Small pigment particles, unknown decomposition products and newly generated chemical compounds are then removed from the skin via blood vessels or the lymphatic system.”
#Baleisis J, Rudys R. Comprehensive examination of tattoo removal using a 150 ps Nd:YAG laser in a porcine model. Sci Rep. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10421900/
Quote: “This tattoo removal technique is based on the photoacoustic effect, which is characterized by the rapid thermal expansion of targeted tissue following fragmentation and the release of mechanical supersonic or acoustic waves, resulting in the destruction of surrounding tissue12. The resulting fragmentation of pigments into smaller fragments allows for their phagocytosis by macrophages and subsequent removal via the lymphatic system13, leading to tattoo lightening14.”
#Kasai K. Picosecond Laser Treatment for Tattoos and Benign Cutaneous Pigmented Lesions (Secondary publication). Laser Ther. 2017
https://pmc.ncbi.nlm.nih.gov/articles/PMC5801452/
Quote: “The different reactions comparing a ps-laser to an ns-laser can be summed up as follows. When an ns-domain Q-switched laser is used, the major reaction which takes place is photothermolysis through a photothermal reaction, with a very small photomechanical effect. However when a ps-laser is used, stress lock-in occurs and the major reaction involves the photoacoustic destruction of the particle, with a minor photothermal component. Therefore more efficient and effective destruction of the particle becomes possible. Also, since heat generation through light absorbance decreases, color dependence for the reactions decreases as well. It is anticipated that the less heat generation will lead to less heat induced complications such as discoloration of the tattoo.”
– Many more cells are injured and are chemically screaming for help. It's like an internal burn wound.
The Brutal Aftermath
Hundreds of thousands of immune cells like Macrophages, stream into the wound to clean up the mess. They order inflammation so your blood vessels open up and water rushes in. Your wounded skin starts to swell up and turn red.
#Tjipta A, Ramadhan H, Lubis RA. Immune Response in Laser Tattoo Removal: A Systematic Review. J Lasers Med Sci. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10843227/
Quote: “Q-switched lasers are characterized by their short pulse duration and high intensities, which result in the rapid heating of pigment particles. The application of this technique has the potential to induce shock waves, thus causing fragmentation of the pigment particles within the dermal layer. However, in response to this injury, the immune system initiates a cascade of events leading to the recruitment of immune cells, including macrophages, neutrophils, and dendritic cells, which play a crucial role in the repair and regeneration of the affected tissue.”
#E., Tianyu, Bi, Chen, Liu, Xiaopeng, Lin, Li, Cao, Yongqian, The Effect of an Er:YAG Laser Combined with a 755 nm Picosecond Laser on Tattoo Removal in a Rat Model, Dermatologic Therapy, 2024
https://onlinelibrary.wiley.com/doi/10.1155/2024/4509910
Quote: “During the laser tattoo removal process, the skin is damaged, and an inflammatory response occurs. During this process, the release of inflammatory factors such as IL-6, MCP-1/CCL-2, and INF-γ enhances the recruitment of macrophages. As the number of macrophages in the skin tissue increases, these cells play a role in phagocytizing tattoo pigments, which is beneficial for their removal.”
Edema (swelling, caused by local fluid accumulation) and erythema (redness of the skin, caused by increased blood flow) are typical side effects of laser tattoo removal.
#Hohman MH, Ramsey ML. Laser Tattoo Removal. [Updated 2025 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK442007/
Quote: “Edema, erythema, and pruritus commonly develop within the first 24 hours after treatment, and they typically subside within 1 to 2 weeks. There may also be crusting or blistering, which should be cleaned to reduce the risk of infection; large blisters may be drained if uncomfortable, but smaller ones tend to resolve spontaneously within a few days.”
– As your cells begin cleaning up casualties and helping with wound healing they also meet loads of hot ink particles. Now is your tattoo actually getting removed – the same immune system that kept it in place is now helping to clean it up. Many of the smallest particles are simply rinsed away by the flood, while Macrophages devour some of them and transport them to your lymph nodes.
In general, tattoo ink particles can travel to lymph nodes via passive transport and active transport via macrophages. The smaller the particles, the more likely they are to move to the lymph nodes. During tattoo removal, ink particles are fragmented into small pieces, which makes them more likely to get taken up by macrophages and transported to some of the several hundred lymph nodes in the adult human body.
#Schreiver et al. Synchrotron-based ν-XRF mapping and μ-FTIR microscopy enable to look into the fate and effects of tattoo pigments in human skin. 2017.
https://www.nature.com/articles/s41598-017-11721-z#Sec8
Quote: “In this investigation, we found a broad range of tattoo pigment particles with up to several micrometers in size in human skin but only smaller (nano)particles transported to the lymph nodes. The exact size limit preventing this translocation is unknown yet. The deposit of particles leads to chronic enlargement of the respective lymph node and lifelong exposure. With the detection of the same organic pigments and inorganic TiO2 in skin and lymph nodes, we provide strong analytical evidence for the migration of pigments from the skin towards regional lymph nodes in humans. So far, this only has been assumed to occur based on limited data from mice and visual observations in humans13, 35. We also were able to prove the presence of several toxic elements, such as Cr and Ni, derived from tattooing. However, elemental deposits in lymph nodes which were not found in the corresponding skin revealed that tattooing might not have been the only route of exposure in these particular individuals whose tissues were removed after their demise”
#Tjipta A, Ramadhan H, Lubis RA. Immune Response in Laser Tattoo Removal: A Systematic Review. J Lasers Med Sci. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10843227/
Quote: “Conversely, in the context of tattoo removal utilizing Q-switched lasers, the laser beam is assimilated by the pigment particles present within the dermis. Q-switched lasers are characterized by their short pulse duration and high intensities, which result in the rapid heating of pigment particles. The application of this technique has the potential to induce shock waves, thus causing fragmentation of the pigment particles within the dermal layer. However, in response to this injury, the immune system initiates a cascade of events leading to the recruitment of immune cells, including macrophages, neutrophils, and dendritic cells, which play a crucial role in the repair and regeneration of the affected tissue. Subsequently, the aforementioned immune cells undergo migration and transport a portion of the shattered pigment particles via the lymphatic system. The primary factor attributed to the phenomenon of tattoo color fading subsequent to Q-switched laser treatment is widely acknowledged to be this.26”
#Barua S. Laser-tissue interaction in tattoo removal by q-switched lasers. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411594/
Quote: “Phagocytosis of the pigment by macrophages is the primary method of elimination. The ruptured fragments are directed by tissue macrophages either to the lymphatic channels or to the regional lymph nodes. Some fragments may be transepidermally eliminated as the posttreatment crust is sloughed off.[5,14]”
#Pazos et al. Tattoo Inks for Optical Biosensing in Interstitial Fluid. 2021.
https://onlinelibrary.wiley.com/doi/full/10.1002/adhm.202101238
Quote: “The smaller pigment particles are removed by dermal macrophage cells and lymphocytes through the lymph nodes in the weeks following each laser procedure, therefore, it is important to space laser sessions at least six weeks apart.[47]”
#Baleisis J, Rudys R. Comprehensive examination of tattoo removal using a 150 ps Nd:YAG laser in a porcine model. Sci Rep. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10421900/
Quote: “The resulting fragmentation of pigments into smaller fragments allows for their phagocytosis by macrophages and subsequent removal via the lymphatic system13, leading to tattoo lightening14. A”
#E., Tianyu, Bi, Chen, Liu, Xiaopeng, Lin, Li, Cao, Yongqian, The Effect of an Er:YAG Laser Combined with a 755 nm Picosecond Laser on Tattoo Removal in a Rat Model, Dermatologic Therapy, 2024
https://onlinelibrary.wiley.com/doi/10.1155/2024/4509910
Quote: “Baranska et al. [10] studies demonstrated that injection site pigment particles were localized in dermal macrophages and thus proposed the pigment capture-release-recapture model. Under physiological conditions, neighbouring macrophages recapture tattoo-pigment-laden macrophages when they die. This process ensures the stability and long-term durability of the tattoo ink. According to recent studies [4, 11], following laser treatment, the destruction of cells containing pigment particles leads to the release of pigment fragments within the tissue. Subsequently, macrophages engulf these fragments, transferring a portion of them and expelling them through the lymphatic vessels.”
– If possible they will be broken down further and ejected from your body via your urine – if not then they will just collect inside your lymph nodes and stay there, probably for the rest of your life.
Once they reach the lymph nodes, the small fragments of ink particles may be transported further into the blood stream via the lymphatic system.
From the bloodstream, experiments in mice suggest that ink particles might also be able to reach the liver. This study was performed on tattooed animals, not on animals whose tattoos were removed with laser treatment. But the principle of ink particles circulating can likely be applied to both scenarios, especially given the fact that laser-treated ink particles are even smaller than those found in the body after a fresh tattoo was applied.
From the liver, it is possible that ink particles will get transported to the kidney and excreted via the urine. However, whether ink particles can be found in urine has not yet been explored in the scientific literature. So while the excretion of ink particles through the urine is anatomically plausible and likely, we cannot say for sure whether it happens.
#National Center for Biotechnology Information (US). Genes and Disease [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 1998-. Blood and Lymph Diseases. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK22211/
Quote: “The lymphatic system (lymph, lymph nodes and lymph vessels) supports the circulatory system by draining excess fluids and proteins from tissues back into the bloodstream, thereby preventing tissue swelling. It also serves as a defense system for the body, filtering out organisms that cause disease, producing white blood cells, and generating antibodies.”
#Sepehri et al. Tattoo Pigments Are Observed in the Kupffer Cells of the Liver Indicating Blood-Borne Distribution of Tattoo Ink. 2017.
Quote: “Results: TEM identified intracellular tattoo pigments in the skin and in lymph nodes. TEM in both groups of tattooed mice showed tattoo pigment deposits in the Kupffer cells in the liver, which is a new observation. TEM detected no pigment in other internal organs. Light microscopy showed dense pigment in the skin and in lymph nodes but not in internal organs. Conclusion: The study demonstrated black and red tattoo pigment deposits in the liver; thus, tattoo pigment distributed from the tattooed skin via the bloodstream to this important organ of detoxification. The finding adds a new dimension to tattoo pigment distribution in the body, i.e., as observed via the blood in addition to the lymphatic pathway.”
Studies using human cadavers have also shown that tattoo ink materials, including organic pigments and heavy metals, can remain in lymph nodes for many years.
#Schreiver, I., Hesse, B., Seim, C., Castillo-Michel, H. et al. Synchrotron-based ν-XRF mapping and μ-FTIR microscopy enable to look into the fate and effects of tattoo pigments in human skin. Scientific Reports. 2017
https://doi.org/10.1038/s41598-017-11721-z
Quote: “In this investigation, we found a broad range of tattoo pigment particles with up to several micrometers in size in human skin but only smaller (nano)particles transported to the lymph nodes. The exact size limit preventing this translocation is unknown yet. The deposit of particles leads to chronic enlargement of the respective lymph node and lifelong exposure. With the detection of the same organic pigments and inorganic TiO2 in skin and lymph nodes, we provide strong analytical evidence for the migration of pigments from the skin towards regional lymph nodes in humans. So far, this only has been assumed to occur based on limited data from mice and visual observations in humans13, 35.”
– So hopefully you got the tattoo from a pro and the ink is not toxic.
Tattoo inks are generally colorants made up of metallic salts that are carried in a solvent along with binders, surfactants and other additives. However, tattoo ink manufacturers aren't required to disclose their ingredients in the US for example so there is no definitive information on the content of each product. But there are some research efforts to analyze inks for the ingredients.
Modern tattoo inks contain organic pigments, but they can also contain heavy metals as chromophores, shading additives, or as contaminants. Titanium, barium, aluminium, and copper are predominantly used as colorants, whereas antimony, arsenic, cadmium, chromium, cobalt, lead, and nickel tend to be contaminants. Some metal oxides (eg, aluminium oxide, titanium oxide) are sometimes added as nanoparticles to create special effects.
During laser removal of tattoos, the ink is broken down into smaller parts and chemical decomposition products, which then travel through the body as the immune system clears the area. There is some evidence that some of these breakdown products could exhibit some limited toxicity in the body, but there is no evidence of laser tattoo removal causing additional health risks that go beyond the original tattoo process.
#Aljubran BA, Ross KE, Alexander U, Lenehan CE. Challenges in laser tattoo removal: the impact of titanium dioxide on photodegradation of yellow inks. Arch Toxicol. 2025
https://pmc.ncbi.nlm.nih.gov/articles/PMC11968486/
Quote: “As tattoos have grown increasingly popular, there has been an increase in their removal. This is commonly achieved using laser treatments. However, certain tattoo inks are resistant to removal using laser methods because of their composition. This includes the removal of yellow pigments and tattoo inks containing titanium dioxide (TiO2). This research examined a series of yellow pigments (PY14, PY74, PY65) and tattoo inks, pre- and post-irradiation, with a QS Nd:YAG laser irradiation at 532 nm. The pigments and products were analysed using a range of techniques, including EDX-SEM, DLS, XRD and GC-MS. Results of this study indicate that the presence of TiO2 alters the laser degradation process of the pigments studied, with observable changes to particle morphologies, particle size, and evolved volatile products. In addition, some of the degradation products were identified to be potentially harmful to the human body.”
#Khunger N, Molpariya A, Khunger A. Complications of Tattoos and Tattoo Removal: Stop and Think Before you ink. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411590/
Quote: “Q-switched lasers have now become the standard for removal of tattoos. However complications can occur, with an incidence of about 5%.[38] On delivery of the laser in the skin, the energy that is absorbed by the pigment is converted to heat, which is the photothermal effect. There is breakage of chemical bonds inside the pigment, which is the photochemical effects. There is a mechanical destruction of the pigments due to photoacoustic effects. Small pigment particles, unknown decomposition products and newly generated chemical compounds are then removed from the skin via blood vessels or the lymphatic system. Pigments remaining in the skin may exhibit different chemical characteristics as compared to nonirradiated pigments again stimulating a reaction of the immune system. Some tattoo pigments containing metals could theoretically break down into toxic chemicals in the body when exposed to light. This has not yet been reported in vivo but has been shown in laboratory tests.”
#Laux et al. A medical-toxicological view of tattooing. 2015.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(15)60215-X/fulltext
Quote: “Meanwhile metals such as titanium, copper, and aluminium are found in ink in concentrations as high as 180·9 g/kg, 31·3 g/kg, and 5·9 g/kg, respectively (Boccha B, unpublished), and a survey from Denmark16 reported high concentrations for toxic metals such as chromium (31 mg/kg), nickel (18 mg/kg), and lead (10 mg/kg).”
#Islam, P.S., Chang, C., Selmi, C. et al. Medical Complications of Tattoos: A Comprehensive Review. 2016.
https://link.springer.com/article/10.1007/s12016-016-8532-0
Quote: “Traditional tattoos use particulate matter pigment suspended in a diluent to deliver the material to the dermis. Most traditional colored inks involve the use of metals, including heavy metals. Black tattoo ink is formulated with a combination of iron salts and carbon. More recently, dyes have been used in tattooing, in part to avoid the use of heavy metals and in part to provide a wider variety of color and to generate more vibrant colors. Dyes are soluble compounds that attach to a substrate by electrostatic forces. The dyes used for tattooing are created for printer ink and for paint colorants. These modern-day colorants are mainly organic, containing azo or polycyclic pigments. Nonetheless, antimony, cadmium, lead, chromium, cobalt, nickel, and arsenic may still be present as contaminants [9]. Furthermore, many tattoo artists prefer to use traditional granular pigments and may store and use inks and powders for decades. Spectrophotometric analysis of trace metals has revealed the presence of multiple elements at levels exceeding the traditionally accepted safe limit of 1 μg/g [16, 17 (see Table 2)]"
#Jennifer Ouellette. Scientists explore chemistry of tattoo inks amid growing safety concerns. 2022
Quote: “Typical tattoo ink contains one or more pigments (which give the ink its color) within a "carrier package" to help deliver the pigments into the skin. The pigments are the same as those used in paints and textiles. They can be either small bits of solids or discrete molecules, such as titanium dioxide or iron oxide (for white or rust-brown colors, respectively). As for the carrier packages, most ink manufacturers use grain or rubbing alcohol, sometimes with a bit of witch hazel added to the mix to help the skin heal after the tattooing process. There may also be other additives to adjust the viscosity and keep pigment particles suspended in the carrier package.”
There is also a website where researchers share the ingredients of the inks they studied: http://whatsinmyink.com/
#Schreiver et al. Synchrotron-based ν-XRF mapping and μ-FTIR microscopy enable to look into the fate and effects of tattoo pigments in human skin. 2017.
https://www.nature.com/articles/s41598-017-11721-z#Sec8
Quote: “Tattoo pigments consist of either inorganic colorful metals and its oxides, or of polyaromatic compounds, all of which are thought to be biologically inert. It can thus be expected to find a broad range of elements in tattooed human tissue—among them the sensitizers nickel (Ni), chromium (Cr), manganese (Mn), and cobalt (Co)—as parts of color-giving pigments or element contamination 14–17. Besides carbon black, the second most commonly used ingredient of tattoo inks is titanium dioxide (TiO2), a white pigment usually applied to create certain shades when mixed with colorants. The toxicity of TiO2 depends on its speciation (crystal structure) which can be either rutile or the more harmful photocatalytically active anatase18. The latter can lead to the formation of reactive oxygen species when exposed to sunlight. Delayed healing is thus often associated with white tattoos, along with skin elevation and itching19”
#McGovern V. Metal Toxicity: Tattoos: Safe Symbols? Environ Health Perspect. 2005
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1280436/
Quote: “Titanium and aluminum are often used as colorants in tattoos; more worrisome, inks using nonmetal colorants may include traces of antimony, arsenic, beryllium, chromium, cobalt, lead, nickel, and selenium (AESI filed over the latter eight metals). Sivas says the ink used for a 3 by 5 inch tattoo contains 1–23 micrograms of lead, versus the 0.5 micrograms per day permitted under Proposition 65.”
#Jennifer Ouellette. Scientists explore chemistry of tattoo inks amid growing safety concerns. 2022
Quote: “They found that many ingredients didn't appear on the manufacturers' labels, such as one ink that contained ethanol even though it was not listed on the label. And 23 of the inks analyzed thus far show evidence of an azo-containing dye. Such pigments are usually inert, but exposure to bacteria or UV light can cause them to degrade into a nitrogen-based compound that potentially could cause cancer.
Furthermore, says Swierk, "Often the particle sizes used in tattoo inks are very small—less than 100 nanometers in diameter. When you get down to that size regime, you start to have concerns about nanoparticles penetrating into cells, getting into the nucleus and doing damage, possibly causing cancer." About half of the 18 inks analyzed with electron microscopy had particles in this worrisome size range.”
#Schreiver et al. Synchrotron-based ν-XRF mapping and μ-FTIR microscopy enable to look into the fate and effects of tattoo pigments in human skin. 2017.
https://www.nature.com/articles/s41598-017-11721-z#Sec8
Quote: “Tattoos contribute to the elemental load of lymph nodes. A central aim of this study was to assess to what extent tattooing increases the proportion of toxic elements in the body. We found Al, Cr, Fe, Ni and Cu quantitatively elevated in skin and lymph node specimens using ICP-MS analysis (Table 1 and Supplementary Table S2). For donor 4, Cd and Hg concentrations were found increased only in the lymph nodes, but not in the analyzed skin sections. These elements probably result from other tattoos that were not part of this study or other routes of exposure drained through the same lymphatic tissue. Non-quantitative evaluation of the survey scans revealed the presence of Ti, presumably derived from TiO2, in all tattooed skin samples but not in controls.”
– But the majority of ink particles are either still too large or there are just too many of them. So your immune and skin cells – in a brave effort to protect you – once again swallow and bind them in place. This is why a laser tattoo removal usually takes between 5 and 12 sessions – each time a part of the tattoo is transported away and an even larger one cemented in place again.
Removal success and the duration of required laser treatments to remove a tattoo varies strongly from tattoo to tattoo and from person to person. Relevant factors to consider include the age of the tattoo, its depth, its location on the body, and the color/pigments used. Additionally, the skin type of the tattooed person can make it easier or harder for tattoos to be removed by laser treatment.
#Rokhsar C. Tattoo Removal: Statistics, Ways, Results. New York Cosmetic, Skin & Laser Surgery Center. Retrieved August 2025
Quote: “Laser treatment works differently for all patients, depending on the tattoo. The greater the color contrast between the ink and skin, the easier the removal will be, which is why black ink on light-skinned people, is the easiest to remove, while bright colors, such as green and purple, are very difficult to completely erase. Smaller tattoos are also easier to remove, as are older tattoos, because the ink is easier to break down. Taking those factors into consideration, patients should expect to undergo five to 12 laser treatment sessions and must wait a month between treatments, so expect the entire tattoo-removal process to last six months to a year.”
#Removery. Ultimate Facts Guide About Tattoo Removal. Retrieved August 2025
https://removery.com/tattoo-removal/laser-tattoo-removal-facts/
Quote: “These insights stem from Removery’s fusion of quantitative and qualitative methods. Our research draws from internal databases, clinical studies, and client surveys, as well as data spanning over 1.6 million tattoo removal treatments from 2019-2024 across the United States, Australia, and Canada. Rigorous statistical analysis, trend modeling, and privacy safeguards underpinned our approach.”
To estimate the required number of laser treatment sessions to remove a specific tattoo, the Kirby-Desai scale (https://0x24a537r9.github.io/kirbydesai/) is sometimes used. And recently, a new predictive model (Smarrito-Pineau Model) has been proposed.
#Kirby W, Desai A, Desai T, Kartono F, Geeta P. The Kirby-Desai Scale: A Proposed Scale to Assess Tattoo-removal Treatments. J Clin Aesthet Dermatol. 2009
https://pmc.ncbi.nlm.nih.gov/articles/PMC2923953/
Quote: “Background: As tattoos have become increasingly popular in the Western world, tattoo-removal requests have also increased, as patients’ personal identities advance. Laser tattoo removal is the current treatment of choice given its safety and efficacy. However, due to varying types of tattoos, it has been difficult to quantify the number of laser treatments required with certainty when discussing laser tattoo removal with our patients. Objective: To propose a practical numerical scale to assess the number of laser tattoo-removal treatments necessary to achieve satisfactory results. Methods and materials: A retrospective chart review was performed on 100 clinic patients who presented for laser tattoo removal. An algorithm was proposed to assign a numerical score to each tattoo across six different categories (skin type, location, color, amount of ink, scarring, and layering). The cumulative score (Kirby-Desai score) is proposed to correlate with the number of treatment sessions required for satisfactory tattoo removal. Results: A correlation coefficient of 0.757 was achieved, with satisfactory tattoo removal in all subjects (N=100, p<0.001). Conclusion: We propose the Kirby-Desai scale as a practical tool to assess the number of laser tattoo-removal sessions required, which will translate into a more certain cost calculation for the patient.”
#Menozzi-Smarrito C, Pineau N. A New Predictive Model for Tattoo Removal: Leveraging Patient and Tattoo Characteristics. J Cosmet Dermatol. 2025
https://pmc.ncbi.nlm.nih.gov/articles/PMC12274964/
Quote: “Introduction
The objective of this research was to investigate key parameters impacting the process of tattoo removal and to propose a new predictive model for estimating the number of sessions necessary for the complete removal of black tattoos with a picosecond laser.
Methods
This prospective study involved 116 patients aged 18–62 years who visited our center between January 2020 and June 2024 for the full treatment of black tattoos. Data were collected about patient (age, gender, and phototype), tattoo specifics (age, size, location, ink density, country/region where the tattoo was created, if it was realized by an amateur or a professional tattoo artist, tattoo settings) and the total number of laser treatments. Treatments were performed with a Picosure laser (Cynosure, USA) at 755 nm using fluences of 0.69–6.37 J/cm2 a pulsation length of 650 ps. Multi‐way analysis of variance was performed to estimate the effect of each parameter. In order to estimate the number of sessions for complete tattoo removal, a predictive model was then created by the addition of parameter interactions (two‐by‐two only). Additional factors were included or excluded by a stepwise approach (backward and forward). Inclusion and exclusion criteria were based on p value thresholds.
Results and Conclusion
ANOVA results revealed that ink density had the most significant impact on laser tattoo removal, followed by tattoo location, age, and design technique (dots, lines, or both). Country/region of origin and whether the tattoo was amateur or professional had a marginal effect, whereas design type (drawing or letters), patient age, skin type, gender, and tattoo size showed no significant influence. Based on these findings, we developed a new efficient predictive tool to estimate the number of picosecond laser sessions required for complete black tattoo removal. The Smarrito–Pineau (SP) model could be readily implemented since variables are easily assessable. It was possible to provide personalized treatment plans and enhance patient satisfaction by offering more accurate treatment timelines.”
– You get to enjoy watching this process happening in real time. Within the first few hours the frosting under your skin fades and the skin around the tattoo feels like a bad sunburn. Red, swollen and stingy. Often it raises with fluid filled burn blisters that you should leave alone.
#Hohman MH, Ramsey ML. Laser Tattoo Removal. [Updated 2025 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK442007/
Quote: “Edema, erythema, and pruritus commonly develop within the first 24 hours after treatment, and they typically subside within 1 to 2 weeks. There may also be crusting or blistering, which should be cleaned to reduce the risk of infection; large blisters may be drained if uncomfortable, but smaller ones tend to resolve spontaneously within a few days.”
– As the pain calms down it is replaced by soreness. During the next few days the wound will remain red, swollen and tender and begin to itch – the itching is a direct consequence of your immune cells actively healing you, so maybe that gives you some comfort.
#Mitwalli H, Alfurayh N. Tattoo Regret, Complications, and Removal: A Cross-Sectional Study among Tattooed Individuals in Saudi Arabia. Dermatol Res Pract. 2024
https://pmc.ncbi.nlm.nih.gov/articles/PMC10843227/
Quote: “There are a total of eight studies that will be reviewed in this study. Table 1 provides information on the immune responses of individuals after undergoing tattoo removal procedures, including the research problem and objectives, patient age, and the type of laser used in tattoo removal. This table provides detailed information on the immune responses found in these studies, with the most common being hypersensitivity reactions, itching, and anaphylaxis.”
#Xu J, Zanvit P, Hu L, Tseng PY, Liu N, Wang F, Liu O, Zhang D, Jin W, Guo N, Han Y, Yin J, Cain A, Hoon MA, Wang S, Chen W. The Cytokine TGF-β Induces Interleukin-31 Expression from Dermal Dendritic Cells to Activate Sensory Neurons and Stimulate Wound Itching. Immunity. 2020
https://pmc.ncbi.nlm.nih.gov/articles/PMC7362873/
Quote: “Cutaneous wound healing is associated with the unpleasant sensation of itching. Here we investigated the mechanisms underlying this type of itch, focusing on the contribution of soluble factors released during healing. We found high amounts of interleukin 31 (IL-31) in skin wound tissue during the peak of itch responses. Il31−/− mice lacked wound-induced itch responses. IL-31 was released by dermal conventional type 2 dendritic cells (cDC2s) recruited to wounds and increased itch sensory neuron sensitivity. Transfer of cDC2s isolated from late-stage wounds into healthy skin was sufficient to induce itching in a manner dependent on IL-31 expression. Addition of the cytokine TGF-β1, which promotes wound healing, to dermal DCs in vitro was sufficient to induce Il31 expression, and Tgfbr1f/f CD11c-Cre mice exhibited reduced scratching and decreased Il31 expression in wounds in vivo. Thus, cDC2s promote itching during skin would healing via a TGF-β-IL-31 axis with implications for treatment of wound itching.”
– After about a week the wound may crust over as new healthy and pink skin replaces the injured one. Things get slowly back to normal. Your tattoo will usually be noticeably lighter, although not that much if this was your first session. Over the next few weeks it will still get a bit lighter as your immune system keeps transporting parts of it away.
#Removery. How Much will My Tattoo Fade After the First Laser Treatment? Retrieved August 2025
https://removery.com/blog/tattoo-removal-first-session/
Quote: “On average it takes around 3-5 sessions to start seeing the tattoo fading. It’s actually common to see the tattoo appear brighter after the first session due to the ink particles being disturbed. Rest assured, that your body will be removing the tattoo and you’ll typically start to see the fading process around 3-5 sessions.”
#Loh & Celine Skin Specialist Clinic. What Does A Tattoo Look Like After One Removal Session?. Retrieved August 2025
https://www.lohcelineskinspecialist.com/what-does-a-tattoo-look-like-after-one-removal-session/
Quote: “The visible effects of tattoo removal after one session vary depending on individual factors but generally show early signs of fading and skin texture changes.
A. Colour Fading
After one session, you may notice slight fading in the tattoo’s colour, particularly if the tattoo contains dark or black ink, which absorbs laser energy more efficiently. Colours like black, blue, and green often show more noticeable changes, while lighter colours may require more sessions to start fading. While the degree of colour change varies, patients can generally expect gradual lightening in heavily pigmented areas.”
#Tjipta A, Ramadhan H, Lubis RA. Immune Response in Laser Tattoo Removal: A Systematic Review. J Lasers Med Sci. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10843227/
Quote: “Conversely, in the context of tattoo removal utilizing Q-switched lasers, the laser beam is assimilated by the pigment particles present within the dermis. Q-switched lasers are characterized by their short pulse duration and high intensities, which result in the rapid heating of pigment particles. The application of this technique has the potential to induce shock waves, thus causing fragmentation of the pigment particles within the dermal layer. However, in response to this injury, the immune system initiates a cascade of events leading to the recruitment of immune cells, including macrophages, neutrophils, and dendritic cells, which play a crucial role in the repair and regeneration of the affected tissue. Subsequently, the aforementioned immune cells undergo migration and transport a portion of the shattered pigment particles via the lymphatic system. The primary factor attributed to the phenomenon of tattoo color fading subsequent to Q-switched laser treatment is widely acknowledged to be this.”
#Baleisis J, Rudys R. Comprehensive examination of tattoo removal using a 150 ps Nd:YAG laser in a porcine model. Sci Rep. 2023
https://pmc.ncbi.nlm.nih.gov/articles/PMC10421900/
Quote: “In recent years, picosecond (ps) lasers have emerged as a more promising option for tattoo removal, as they have been shown to be more effective in terms of tattoo clearance and pain management in both preclinical10 and clinical studies11.
This tattoo removal technique is based on the photoacoustic effect, which is characterized by the rapid thermal expansion of targeted tissue following fragmentation and the release of mechanical supersonic or acoustic waves, resulting in the destruction of surrounding tissue12. The resulting fragmentation of pigments into smaller fragments allows for their phagocytosis by macrophages and subsequent removal via the lymphatic system13, leading to tattoo lightening14.”
#Barua S. Laser-tissue interaction in tattoo removal by q-switched lasers. J Cutan Aesthet Surg. 2015
https://pmc.ncbi.nlm.nih.gov/articles/PMC4411594/
Quote: “Phagocytosis of the pigment by macrophages is the primary method of elimination. The ruptured fragments are directed by tissue macrophages either to the lymphatic channels or to the regional lymph nodes. Some fragments may be transepidermally eliminated as the posttreatment crust is sloughed off.[5,14]”
– Modern laser tattoo removal has gotten very good, so if you chose an experienced professional you should be completely healed after two months – but if you did not or if you had the procedure done with older tech, sometimes there might be a slight scar or the colour of your skin may have slightly changed in places. Although this is pretty rare nowadays, please do your research who you are allowing to shoot lasers at you.
#Removery. How Long To Wait Between Laser Tattoo Removal Treatments? Retrieved August 2025
https://removery.com/au/blog/how-long-to-wait-between-laser-tattoo-removal-treatments/
Quote: “Ideally, the waiting time of about six to eight weeks between treatments will allow for complete healing. If the tattooed area is still scabbed or visibly healing from the last laser treatment, it is beneficial to wait even longer.”
#GoodbyeTattoos. How Long Between Tattoo Removal Sessions? Everything You Need to Know. 2025
https://goodbyetattoos.com/tattoo-removal-sessions-wait-time/
Quote: “Most professionals recommend waiting 6 to 8 weeks between laser tattoo removal sessions. This allows your skin enough time to heal and your immune system to flush out the broken ink particles. In some cases, especially for larger or more stubborn tattoos, waiting 8 to 12 weeks may be more effective.”
Before the development of modern medical lasers for tattoo removal, other types of lasers such as Argon lasers and CO2 lasers were used for this purpose. They were much less specific, and more importantly, much more destructive, often resulting in deep scarring.
#Bernstein EF. Laser tattoo removal. Semin Plast Surg. 2007
https://pmc.ncbi.nlm.nih.gov/articles/PMC2884836/
Quote: “Lasers have also been used to nonselectively remove tattoos by heating and tissue destruction since the 1970s.32,33,34,35,36 The argon laser is a laser that destroys tissue by nonselective heating and emits a blue or green continuous laser beam at 488 or 514 nm. Although tattoos selectively take up this green light if they are black, because the lasers are not pulsed, nonspecific heating and tissue destruction takes place. Thus, the heat spreads from the tattoo granules to the surrounding skin, destroying not only the tattoo but also the skin. This results in scarring in a fashion similar to the carbon dioxide laser. The carbon dioxide laser emits at a wavelength of 10,600 nm, targeting water as the chromophore. The carbon dioxide laser thus ablates superficial layers of skin, resulting in removal of some of the tattoo pigment with significant inflammation and results in scarring. This laser has been used for almost 25 years for tattoo removal, rarely removing the tattoo completely and almost always leaving a scar.37,38,39 The carbon dioxide laser is nonspecific but able to remove superficial layers of skin more selectively than some other nonspecific modalities. Nonetheless, the result is still most often partial tattoo removal with significant hypopigmentation and scarring (Fig. 2). The continuous argon laser produces a similar scarred appearance in treated tattoos as seen after carbon dioxide laser treatment.40,41,42,43 These destructive modalities represent the first attempts to more selectively remove tattoos than previous chemical or abrasive techniques. They presaged the modern age of laser tattoo removal.”
– The best case is that after a number of sessions your tattoo is no longer visible, or only very, very faintly. If it will completely disappear depends on the size of your tattoo, the colours that were used, how deep the ink was injected and to a degree – how good of a job your body is doing at cleaning up the mess.
Removal success and the duration of required laser treatments to remove a tattoo varies strongly from tattoo to tattoo and from person to person. Relevant factors to consider include the age of the tattoo, its depth, its location on the body, and the color/pigments used. Additionally, the skin type of the tattooed person can make it easier or harder for tattoos to be removed by laser treatment.
To estimate the required number of laser treatment sessions to remove a specific tattoo, the Kirby-Desai scale (https://0x24a537r9.github.io/kirbydesai/) is sometimes used.
#Kirby W, Desai A, Desai T, Kartono F, Geeta P. The Kirby-Desai Scale: A Proposed Scale to Assess Tattoo-removal Treatments. J Clin Aesthet Dermatol. 2009
https://pmc.ncbi.nlm.nih.gov/articles/PMC2923953/
Quote: “Background: As tattoos have become increasingly popular in the Western world, tattoo-removal requests have also increased, as patients’ personal identities advance. Laser tattoo removal is the current treatment of choice given its safety and efficacy. However, due to varying types of tattoos, it has been difficult to quantify the number of laser treatments required with certainty when discussing laser tattoo removal with our patients. Objective: To propose a practical numerical scale to assess the number of laser tattoo-removal treatments necessary to achieve satisfactory results. Methods and materials: A retrospective chart review was performed on 100 clinic patients who presented for laser tattoo removal. An algorithm was proposed to assign a numerical score to each tattoo across six different categories (skin type, location, color, amount of ink, scarring, and layering). The cumulative score (Kirby-Desai score) is proposed to correlate with the number of treatment sessions required for satisfactory tattoo removal. Results: A correlation coefficient of 0.757 was achieved, with satisfactory tattoo removal in all subjects (N=100, p<0.001). Conclusion: We propose the Kirby-Desai scale as a practical tool to assess the number of laser tattoo-removal sessions required, which will translate into a more certain cost calculation for the patient.”
Google Sites
Report abuse