Chemical Family: Phenols

Therapeutic Properties

analgesic 1, 2

anti-inflammatory12, 13

antibacterial3, 4, 5, 6, 7, 8

antifungal9, 10

antifungal (candida)11

antioxidant14, 15, 16, 17, 18,

antispasmodic21, 22




liver protective15, 18

Medical Actions

    • The analgesic action of thymol suggests effects in both skeletal and smooth muscle (1,2).

    • Thymol has a long-lasting antibacterial action (8), and has shown good efficacy against some antibiotic-resistant strains (5,6).

    • Thymol inhibits the growth of Cryptococcus neoformans, an opportunistic fungus that often causes problems in the last phase of AIDS (10).

    • The antimicrobial action of thymol is suggestive of therapeutic effects in infections of the skin, gums, throat, lungs, and GI tract.

    • The anti-inflammatory action of thymol involves inhibition of COX-1 and COX-2, and so is similar to medications such as aspirin and ibuprofen. Thymol also inhibits neutrophil chemotaxis (12).

    • Thymol is one of the most potent antioxidantessential oil constituents.

    • Its antioxidant action has been experimentally linked to inhibition of erythrocyte cell death, suggesting possible use in counteracting anemia or the impairment of microcirculation (19).

    • Experimental evidence suggests antioxidant-related protection that could minimise the side-effects of gamma radiation (16).

    • Thymol has shown in vitro antitumoral effects in cells for mouse melanoma (23).

    • Medicines that inhibit acetylcholinesterase are used in cases of cognitive dysfunction, for example people with Alzheimer's disease (26,27).

Safety Concerns

Thymol can cause skin irritation if used at 5% or more, though this is uncommon. At 1% it has never been known to cause any adverse skin reaction (Robert Tisserand, private communication).

Thymol inhibits platelet aggregation (29, 30). Essential oils high in thymol should therefore be avoided, especially in high or oral doses, before major surgery, and in anyone taking blood-thinning medication, or with blood coagulation issues.


Thymol is found in greatest quantity in the thymol chemotype of thyme oil (up to 74%), Monarda citrodora var citriodora (60%) and ajowan (up to 55%).

Thymol is isomeric with carvacrol, and their pharmacological properties are similar. They are invariably found together in essential oils.


Beer A-M, Lukanov J, Sagorchev P (2007) Effect of thymol on the spontaneous contractile activity of the smooth muscles. Phytomedicine 14:65-69.

Haeseler G, Maue D, Grosskreutz J et al (2002) Voltage-dependent block of neuronal and skeletal muscle sodium channels by thymol and menthol. European Journal of Anaesthesiology 19:571-579.

Knobloch K, Pauli A, Iberl B et al (1989) Antibacterial and antifungal properties of essential oil components. Journal of Essential Oil Research 1:119-128

Mohammed MJ, Al-Bayati FA (2009) Isolation and identification of antibacterial compounds from Thymus kotschyanus aerial parts and Dianthus caryophyllus flower buds. Phytomedicine 16:632-637

Palaniappan K, Holley RA (2010) Use of natural antimicrobials to increase antibiotic susceptibility of drug resistant bacteria. International Journal of Food Microbiology 140(2-3):164-168

Shin S, Kim JH (2005) In vitro inhibitory activities of essential oils from two Korean thymus species against antibiotic-resistant pathogens. Archives of Pharmaceutical Research 28(8):897-901

Trombetta D, Castelli F, Sarpietro MG et al (2005) Mechanisms of antibacterial action of three monoterpenes. Antimicrobial Agents and Chemotherapy 49(6):2474-2478

Zarrini G, Delgosha ZB, Moghaddam KM et al (2010) Post-antibacterial effect of thymol.Pharmceutical Biology (6):633-636

Ahmad A, Khan A, Singh N et al (2010) Proton translocating ATPase mediated fungicidal activity of eugenol and thymol. Fitoterapia 81(8):1157-1162

Viollon C, Chaumont JP (1994) Antifungal properties of essential oils and their main components upon Cryptococcus neoformans. Mycopathologia 128(3):151-153

Ahmad A, Khan A, Akhtar F, et al (2011) Fungicidal activity of thymol and carvacrol by disrupting ergosterol biosynthesis and membrane integrity against Candida. European Journal of Clinical Microbiology & Infectious Diseases 30(1):41-50

Azuma Y, Ozana, N, Ueda Y et al (1986) Pharmacological studies on theanti-inflammatory action of phenolic compounds. Journal of Dental Research 65(1):53-56

Marsik P, Kokoska L, Landa P et al (2005) In vitro inhibitory effects of thymol and quinones of Nigella sativa seeds on cyclooxygenase-1- and -2-catalyzed prostaglandin E2 biosyntheses. Planta Medica 71:739-742

Aeschbach R, Loliger J, Scott BC et al (1994) Antioxidant actions of thymol, carvacrol, 6-gingerol, zingerone and hydroxytyrosol. Food & Chemical Toxicology 32:31-36

Alam K, Nagi MN, Badary OA et al (1999) The protective action of thymol against carbon tetrachloride hepatotoxicity in mice. Pharmacological Research 40:159-163

Archana PR, Rao BN,Ballal M et al (2009) Thymol, a naturally occurring monocyclic dietary phenolic compound protects Chinese hamster lung fibroblasts from radiation-induced cytotoxicity Mutation Research 680:70-77

Braga PC, Dal Sasso M, Culici M et al (2005) Antioxidant potential of thymol determined by chemiluminescence inhibition in human neutrophils and cell-free systems. Pharmacology 76:61-68

Jimenez J, Navarro MC, Montilla MP et al, (1993) Thymus zygis oil: its effects on CC14-induced hepatotoxicity and free radical scavenger activity. Journal of Essential Oil Research 5:153-158

Mahmud H, Mauro D, Foller M et al (2009) Inhibitory effect of thymol on suicidal erythrocyte death. Cellular Physiology and Biochemistry 24(5-6):407-4014

Vardar-Unlu G, Candan F, Sokmen A et al (2003) Antimicrobial andantioxidant activity of the essential oil and methanol extracts of Thymus pectinatus Fisch. et Mey. var. pectinatus (Lamiaceae). Journal of Agricultural & Food Chemistry 51:63-67

Beer A-M, Lukanov J, Sagorchev P (2007) Effect of thymol on the spontaneous contractile activity of the smooth muscles. Phytomedicine 14:65-69

Van Den Broucke CO, Lemli J A (1982) Antispasmodic activity ofOriganum compactum. Planta Medica 45:188-190

He L, Mo H, Hadisusilo S et al (1997) Isoprenoids suppress the growth of murine B16 melanomas in vitro and in vivo. Journal of Nutrition 127:668-674

Astani A, Reichling J, Schnitzler P (2010) Comparative study on the antiviral activity of selected monoterpenes derived from essential oils. Phytotherapy Research 24(5):673-679

Futami T (1984) [Actions and mechanisms of counterirritants on the muscular circulation]. Nippon Yakurigaku Zasshi 83:219-226

Jukic M, Politeo O, Maksimovic M, et al (2007) In vitroacetylcholinesterase inhibitory properties of thymol, carvacrol and their derivatives thymoquinone and thymohydroquinone. Phytotherapy Research 21(3):259-261

Orhan I, Kartal M, Kan Y, et al (2008) Activity of essential oils and individual components against acetyl- and butyrylcholinesterase. Zeitschrift fur Naturforschung C 63(7-8):547-553.

Muhlbauer RC, Lozano A, Palacio S et al (2003) Common herbs, essential oils, and monoterpenes potently modulate bone metabolism. Bone 32:372-380

Enomoto S, Asano R, Iwahori Y et al (2001) Hematological studies on black cumin oil from the seeds of Nigella sativa L. Biological & Pharmaceutical Bulletin 24:307-310

Okazaki et al (2002) Human platelet aggregation inhibitors from thyme (Thymus vulgaris L.). Phytotherapy Research 16(4):398-399