PrEP (Pre-exposure Prophylaxis) is medication that you can take to stop yourself from getting HIV. It contains drugs that are commonly used to treat HIV - emtricitabine (FTC) and tenofovir DF (TDF).
Taking PrEP before having sex means that it blocks HIV if it gets into your body, stopping it from infecting you.
Who should take PrEP?
If you are at risk of being exposed to HIV, you should consider taking PrEP. Those at highest risk are:
How and when do you take PrEP?
You can take PrEP every day.
In certain circumstances, you can also take it as and when you need it, in the following pattern:
This is not an option for women and trans people who want protection for vaginal sex, or for people who have Hepatitis B.
Missing a tablet
If you take your PrEP every day, you will still have very high protection if you miss the occasional dose. Therefore, taking it daily offers you the best protection.
If you take PrEP occasionally and do miss a dose, don't panic. A late dose provides some protection. For anal sex, four doses every week provides more than 95% protection.
How safe and effective is PrEP?
PrEP is extremely effective at preventing HIV infection if it is taken correctly. This has been shown in major PrEP studies.
The drugs used in PrEP are the same as those used in HIV medications, taken my thousands of people living with HIV. They have no serious side effects and are very safe.
If you get mild side effects, they can occur for the first week or so, but then they usually stop.
You might experience nausea, headaches and tiredness. In very rare cases, PrEP might affect kidney function. This is why it is important to go for kidney function tests as recommended.
If you forget to take your PrEP and become HIV positive, there is a small risk of resistance to HIV medication. However, this was very rare in the PrEP studies.
28th August 2025
