How long does it take for Truvada to work?

Truvada HIV pre-exposure prophylaxis (PrEP) reaches maximum effectiveness after 7 days of daily use for receptive anal sex (bottoming). It takes about 21 days of daily use for protection for receptive vaginal sex or injected drug use. No data are available for insertive anal sex (topping) or insertive vaginal sex.

PrEP pills, if used daily, are over 99% effective at preventing HIV infection from sex. Among people who inject drugs, PrEP pills reduce the risk of getting HIV by at least 74%.

PrEP works best when you take your medicine as instructed by your healthcare provider. Effectiveness declines if not taken consistently.

Descovy, another oral PrEP regimen similar to Truvada, is not approved by the FDA for use in people born female (assigned female at birth) who are at risk of getting HIV infection from vaginal sex, because its effectiveness has not been studied.

How long does Truvada stay in your system?

It takes up to 93.5 hours, or almost 4 days to fully eliminate a dose of Truvada from your system. Truvada contains two antiviral agents, tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC), in one oral tablet taken once a day.

Truvada half-life

How long a drug stays in your system depends on its half-life. The half-life is the amount of time it takes for half (50%) of a drug to be removed from your body. It is generally accepted that it takes 5.5 half-lives for a drug to be fully removed from the body.

Following a single oral dose of Truvada, the plasma half-life is approximately 10 hours for emtricitabine (FTC) and 17 hours for tenofovir disoproxil fumarate (TDF). For elimination, 5.5 half-lives would be equal to 55 hours for the emtricitabine (FTC) component and 93.5 hours for the tenofovir disoproxil fumarate (TDF) component.

Related questions

• How does Truvada work to prevent HIV?
• Truvada vs Descovy: How do they compare for HIV and PrEP?
• Which medications help prevent HIV infection?

What is Truvada approved for?

Truvada is an oral tablet, taken once daily with or without food. It is:

• used with other HIV medicines to treat human immunodeficiency virus (HIV)-1 infection in adults and children weighing at least 17 kg.
• used for pre-exposure prophylaxis of HIV (PrEP) in adults and adolescents weighing at least 35 kg to reduce the risk of sexually acquired HIV-1 infection.

Which drugs are approved for PrEP?

There are three FDA-approved medicines used for pre-exposure prophylaxis (PrEP) in the U.S:

• Truvada (tenofovir disoproxil fumarate and emtricitabine) - an oral tablet taken once a day (also available as generic formulation).
• Descovy (emtricitabine and tenofovir alafenamide) - an oral tablet taken once a day.
• Apretude (cabotegravir) - a long-acting intramuscular injection given by a healthcare provider every 2 months.

Related: How long does it take Apretude to work?

This is not all the information you need to know about Truvada (tenofovir disoproxil fumarate and emtricitabine) for safe and effective use and does not take the place of your healthcare provider's directions. Review the full product information and discuss this information and any questions you have with your doctor or other healthcare provider.