- PrEP = pre-exposure prophylaxis — HIV medicine taken before exposure.
- Taken as prescribed it's about 99% effective at preventing HIV from sex.
- It comes as a daily pill or a long-acting injection.
- It's for HIV-negative people — and it's often free or low-cost.
01. What does PrEP actually mean?
PrEP is short for pre-exposure prophylaxis. Break that down and it's simple: pre-exposure means "before contact," and prophylaxis is just the medical word for "something that prevents." So PrEP is medicine you take before any exposure to HIV, to stop it from taking hold.
It's the same idea as taking anti-malaria tablets before travelling somewhere with malaria — you protect yourself in advance rather than waiting to get sick. PrEP has been used since 2012 and is recommended by the CDC, WHO and health services worldwide. People sometimes call it "the HIV-prevention pill," and in LGBTQ+ communities you'll often just hear "being on PrEP."
02. How does PrEP work?
HIV needs to get into your cells and start copying itself to establish an infection. PrEP puts a protective level of antiviral medicine into your bloodstream and the tissues where exposure happens, so that if HIV shows up, it can't get a foothold and gain traction. The virus is blocked before it can spread.
That's why taking it consistently matters: the protection comes from having enough medicine in your body at the moment of exposure. Skip a lot of doses and the shield thins out. Take it as prescribed and the shield stays strong.
03. Who is PrEP for?
PrEP is for HIV-negative people who could be exposed to HIV. You don't need to fit a stereotype — plenty of people take it simply for peace of mind. A provider will often suggest it if you:
- Have sex without condoms, or with partners whose status you don't know.
- Have a partner living with HIV (especially if their virus isn't yet undetectable).
- Have had an STI recently, or have used PEP more than once.
- Share injection equipment.
PrEP is used by gay and bisexual men, women, transgender people, straight men and people in serodifferent couples. Curious whether it fits you? Take the 2-minute check.
04. What are the forms of PrEP?
PrEP isn't one product — you have real choices, from a daily tablet to a shot twice a year:
- Daily pills — Truvada (and generics) or Descovy, one tablet a day.
- On-demand "2-1-1" — event-based pills around sex, an option for many gay and bisexual men.
- Apretude — a long-acting injection every 2 months.
- Lenacapavir (Yeztugo) — a breakthrough shot given just twice a year.
Not sure which suits you? Our compare-medications guide lays them out side by side.
05. How effective is PrEP?
Very. When taken as prescribed, PrEP is one of the most effective prevention tools we have:
“PrEP is highly effective for preventing HIV when taken as prescribed.”— U.S. Centers for Disease Control and Prevention
06. Myths vs facts
"PrEP is only for gay men." — Myth. Anyone HIV-negative who may be exposed can benefit, including women and straight men.
"PrEP has awful side effects." — Myth. Most people have none; when they happen they're usually mild and fade in weeks. See the full side-effects guide.
"If I'm on PrEP I don't need condoms." — Half-true. PrEP is excellent against HIV but doesn't stop other STIs, so condoms and testing still matter.
"PrEP is unaffordable." — Myth. It's free or low-cost in many places through insurance and assistance programs — see how to get PrEP.
07. How do I start PrEP?
Getting started is easier than most people expect: a quick HIV test to confirm you're negative, a short chat and some baseline bloods, then your prescription. You'll check in every few months. You can go through a clinic, your doctor, or a telehealth service, and our clinic locator can find a provider near you.
Take the free, private 2-minute check — no sign-up, nothing leaves your browser.
08. Frequently asked questions
QWhat does PrEP stand for?
PrEP stands for pre-exposure prophylaxis — HIV medicine taken before possible exposure so the virus can't take hold if you come into contact with it.
QIs PrEP the same as PEP?
No. PrEP is taken before exposure, on an ongoing basis. PEP is an emergency 28-day course started within 72 hours after a possible exposure.
QDoes PrEP protect against other STIs?
No — PrEP protects against HIV only. Regular STI testing and condoms still matter, and some people add Doxy-PEP for bacterial STIs.
QDo I have to take PrEP forever?
No. You take it while you want protection and can stop safely when you don't. Many people use it for a season of life and restart later.
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