Pre-Exposure Prophylaxis (PrEP) is used to reduce the risk of getting HIV (human immunodeficiency virus).
PrEP works by stopping HIV from getting into your body and making copies of itself (replicating). You'll only be protected from HIV infection if there are high enough levels of PrEP in your body, so it's important to take it correctly.
PrEP can be used by anyone from a community or group that is most at risk of HIV, or people who have sex with people from those networks.
You may benefit from taking PrEP if:
- you're an HIV-negative man having condomless sex with men, and other people who have sex within these networks
- you have a partner (or ex-partner) with HIV
- your partner (or ex-partner) comes from a country with high rates of HIV
- you have condomless sex with a partner(s) and do not know their HIV status
- you're a trans or non-binary person and are regularly having condomless sex
- you exchange sex for money, drugs, shelter or another reason
- you are injecting drugs
Find out more about who is at risk of getting HIV.
Find out more about other at-risk activities.
PrEP comes as tablets that contain 2 medicines called tenofovir disoproxil and emtricitabine. Both medicines are often also used to treat HIV.
You can get PrEP from a health professional at an NHS sexual health clinic.
Key facts
- PrEP does not protect you against other sexually transmitted infections (STIs).
- Common side effects of PrEP include feeling sick (nausea), diarrhoea, bloating, indigestion, headache, feeling tired or weak and sleeping problems. They usually go away after the first couple of weeks.
- If you get stomach side effects while taking PrEP, taking it with or just after food may help.
- Most people can take PrEP every day but some people can take it on demand (just before and after sex).
- If you take PrEP daily for vaginal/frontal sex, it takes 7 days to give maximum protection. If you take it only when you need it for anal sex, you'll be protected about 2 hours after your first double dose.