PrEP

Pre-exposure prophylaxis: HIV medicine, as pills or injections, taken by HIV-negative people to avoid getting HIV; it cuts the risk from sex by about 99%.

PrEP stands for pre-exposure prophylaxis: HIV medication taken by HIV-negative people so they don't get HIV. Taken as prescribed, it cuts the risk of getting HIV from sex by about 99%. In gay life it is less a medicine than a status: "on PrEP" sits on dating profiles next to height and position, and has changed how a whole generation thinks about sex and fear.

It is not a vaccine and not a cure, and it does nothing against syphilis, gonorrhea, chlamydia or other STIs, which is why PrEP comes with regular testing.

How it is taken

• Daily pills. Emtricitabine with tenofovir, sold as Truvada and now widely as cheap generics, or the newer Descovy, one tablet a day.
• On-demand, or 2-1-1. For men who have sex less often and can plan it: two pills 2 to 24 hours before sex, one 24 hours after the first dose, one 24 hours after that. WHO added it to its recommendations in 2019; in the US the CDC describes it as off-label for gay and bisexual men and does not formally recommend it.
• Injections. Cabotegravir every two months, and since 2025 lenacapavir, one injection every six months, approved in the US in June 2025 and recommended by WHO a month later as the first twice-yearly PrEP option.

Any version starts with an HIV test and a talk with a doctor or a sexual health clinic, and continues with tests every few months: kidney checks for the pills, STI screening for everyone.

On the apps

PrEP changed the vocabulary of the apps. Profiles list it as a status, "on PrEP" or "PrEP and U=U friendly", and it is often the context of words like raw and bareback, which went from taboo to ordinary in a few years. In the early years men on PrEP were slut-shamed, often by other gay men; today "are you on PrEP?" is a normal question rather than an accusation.

PrEP, PEP and U=U

Three ideas, often confused:

• PrEP: taken before possible exposure, by HIV-negative people.
• PEP: post-exposure prophylaxis, a 28-day course started as soon as possible, and within 72 hours, after a possible exposure; you get it from a sexual health clinic or an emergency room.
• U=U: an HIV-positive man with an undetectable viral load does not transmit HIV through sex.

Related terms