Your doctor or medical provider will order lab tests before you start PrEP to confirm that the medication is safe for you to take. While you are on PrEP, you will get lab tests several times a year so that your medical provider can monitor your progress.

Note: If your doctor or medical provider has questions about lab tests for PrEP, the Clinician Consultation Center at UCSF provides a hotline specifically for medical providers who have questions. The hotline number is 855-448-7737 (855-HIV-PREP), and it is open from 11 AM to 6 PM Eastern time, Monday-Friday.

Lab Tests Before You Start PrEP

These are the lab tests that are required or recommended before you start PrEP:

• HIV Test: It is ESSENTIAL that you have an HIV test before you start PrEP to confirm that you are HIV-negative. A standard “antibody test” is fine in most cases. Ask for a “viral load test” instead if you believe that you may have been exposed to HIV in the past 6 weeks, or if you have had a flu-like illness (fever, fatigue, body aches, or rash) in the past month. If you’ve had an HIV exposure in the last 72 hours, talk to your provider about getting PEP (post-exposure prophylaxis) first. You can transition to PrEP after you complete PEP. All this is to make sure that you are HIV-negative when you start PrEP. If you start PrEP when you are already HIV-positive, your infection can become drug-resistant, and this may limit your treatment options.
• Kidney Function Tests: You must have tests for kidney function (creatinine level and creatinine clearance) before you start PrEP. If your “creatinine clearance” is less than 60, your kidneys may be too weak for you to take Truvada. Having a value before you start allows your provider to monitor your kidney health while you are on PrEP. Tell your provider about any medications you are taking which can stress the kidneys, such as acyclovir, valacyclovir, cidofovir, ganciclovir, valganciclovir, aminoglycosides, or NSAIDs like ibuprofen).
• Hepatitis B Test: You should be tested for hepatitis B before you start PrEP. If you have not had hepatitis B and have not been vaccinated, ask your provider for the hepatitis B vaccine. If your tests indicate you have an active hepatitis B infection, your medical provider will monitor you carefully. People with hepatitis B do fine on PrEP but if they stop Truvada, it is possible their hepatitis B will quickly get worse.
• Liver Function Tests: Other than screening for Hepatitis B, liver function tests are not recommended or required for people starting PrEP.
• Pregnancy Test: If you could become pregnant, you should be given a pregnancy test before you start PrEP. If you are pregnant, your medical provider will give you additional information about PrEP during pregnancy.

Lab Tests While You Are On PrEP

These are the lab tests that are required or recommended while you are on PrEP:

• HIV Test: See your provider every 3 months for an HIV test. It is ESSENTIAL to confirm you remain HIV-negative while you are on PrEP. If you become HIV-positive, your provider will change your medication right away. Truvada alone is not an effective HIV treatment.
• Other STI Tests: CDC recommends you be tested for STIs at least once every 6 months. Other agencies recommend STI testing every 3 months. You and your medical provider can decide what is appropriate for you based on your sexual activity. STI testing should include blood, urine, and swabs of your throat, rectum, and/or vagina, whichever you use in sexual activity. Important: You may have to specifically request the swabs as some providers do not routinely provide them. Active STIs can go undetected if you have only blood and urine tests.
• Kidney Function Tests: CDC recommends kidney function tests (creatinine level and creatinine clearance) every 6 months. Your doctor may perform this testing more frequently if you have high blood pressure or diabetes or take other medications that stress the kidneys (acyclovir or high doses of NSAIDs like ibuprofen, for example). If creatinine or creatinine clearance is abnormal, you should be retested. If it is abnormal on the second test, your provider may consider stopping PrEP but need not do so if your creatinine clearance remains above 60. Many people can stop Truvada for 3-6 months then resume taking the drug without further kidney issues. For more information about stopping Truvada for medical reasons, please see https://www.facebook.com/PrEPFactsFAQ/posts/896266203823908
• Liver Function Tests: Liver function tests are not recommended or required for monitoring people on PrEP.
• Pregnancy Test: If you could become pregnant, you should be given a pregnancy test every 3 months while you’re on PrEP. If you become pregnant, your medical provider will give you additional information about PrEP during pregnancy.

To Learn More About Creatinine and Creatinine Clearance

Read this article.