PrEP (pre-exposure-prophylaxis) is a medication taken by HIV-negative people that prevents you from getting HIV.
Taking PrEP before being exposed to HIV means there’s enough drug inside you to block HIV if it gets into your body – before it has the chance to take hold. It’s highly effective at stopping HIV from being transmitted when taken correctly.
PrEP offers protection during vaginal/frontal and anal sex. It’s safe to use for trans women and trans feminine people and is effective regardless of any gender-affirming surgeries that you've had, including vaginoplasty.
A long-acting injectable PrEP has been approved by the Food and Drug Administration (FDA) but it is not yet available in the UK.
PrEP and hormone treatment
PrEP doesn’t affect or interact with your hormone treatment.
The British HIV Association guidelines note that there are no known interactions between PrEP and gender-affirming hormones. PrEP will not stop any hormones you are taking from working.
PrEP does not cause fat redistribution in the body or face.
Is PrEP right for you?
PrEP might be right for you if you’re HIV negative and have sex in a variety of situations where condoms are not easily or always used. It gives you empowerment, particularly if you are a receptive partner, or bottom, by taking control over protecting yourself from HIV transmission.
Quote textPrEP is peace of mind for me and allows me to have the kind of sex I want.
How to take PrEP
The way you take PrEP depends on the type of sex you have, but most people choose to take PrEP every day.
PrEP can be taken in different ways to protect against HIV:
- Daily: taking one pill a day, starting with a double dose.
- Four pills a week: taking four pills a week consistently.
- On-demand/ event-based: taking PrEP only around the time you have sex. Pills are taken a few hours before sex and for up to seven days after.
On-demand/ event-based PrEP has different dosing recommendations depending on the type of sex you are having:
- Receptive anal and insertive vaginal/neovaginal or anal sex: PrEP started with a double dose (two pills) 2-24 hours before sex, and a single dose (one pill) daily until 2 days after the last time you have sex.
- Receptive vaginal/neovaginal sex: PrEP started with a double dose (two pills) 2-24 hours before sex, one tablet daily for seven days after.
PrEP is very safe and serious side effects are very rare. A few people experience nausea, headaches or tiredness which tend to only last a few days or weeks.
The drugs most commonly used for PrEP are emtricitabine and tenofovir (which are combined in a single tablet).
PrEP and STIs
PrEP only protects against HIV, not other sexually transmitted infections (STIs). If you’re taking PrEP, using condoms helps prevent other STIs.
Before taking PrEP
Before taking PrEP, have a full sexual health screen at a local clinic, including an HIV test and a test for kidney function.
While taking PrEP, test for HIV and all other STIs every three months.
Where to obtain PrEP
You can get PrEP for free on the NHS from a sexual health clinic.
PrEP can also be bought from a reliable source.
If you want to stop taking PrEP
If you want to stop taking PrEP for any reason and are taking it daily, you should continue taking it for seven days after sex. If you are taking ‘on-demand dosing’ you should continue taking PrEP for the recommended time after sex, either 2 or 7 days after the last time you have sex without a condom.
Get tested for HIV before you start taking PrEP again. If you have acquired HIV and begin taking PrEP, you may develop resistance to the drugs used for PrEP which could affect future treatment options.
If you're living with hepatitis B, be aware that PrEP can suppress the virus – you should always use daily dosing of PrEP and shouldn't stop taking PrEP until you've got advice from your doctor.
Find out more about PrEP
PEP
PEP (post-exposure prophylaxis for HIV) is a treatment that can stop an HIV infection after the virus has entered a person’s body (for example, if you’ve had sex and the condom fails). To work, PEP must be taken within 72 hours (three days), and ideally should be taken within 24 hours.
If you think you've been at risk of acquiring HIV, it might be worth accessing post-exposure prophylaxis (PEP).
You can access PEP from a sexual health clinic or A&E. Tell your doctor if you're taking any hormones and any other drugs or medications. There are very few interactions with oestrogen treatment.
