What is PrEP?
PrEP (Pre-Exposure Prophylaxis) is a daily medication taken by HIV-negative people to prevent them from acquiring HIV. The most widely used formulation is a combination pill containing tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC), sold under the brand name Truvada. When taken consistently, PrEP is over 99% effective at preventing HIV transmission through sex.
Who should consider PrEP?
PrEP is recommended for HIV-negative people at high risk of HIV. This includes: men who have sex with men (MSM) who have multiple partners or inconsistent condom use; people whose partners are HIV positive and not on treatment (or whose viral load is not fully suppressed); and anyone who injects drugs and shares equipment. A sexual health clinician can help you assess whether PrEP is appropriate for your situation.
How is PrEP taken?
PrEP can be taken in two ways. Daily PrEP involves taking one pill every day at the same time, regardless of sexual activity. Event-based (on-demand) PrEP involves taking two pills 2–24 hours before sex, one pill 24 hours later, and one pill 48 hours after the first dose. On-demand PrEP has been shown to be highly effective in MSM but is not recommended for people who inject drugs, transgender women, or for protection against HIV via receptive vaginal sex.
How do you get PrEP on the NHS?
PrEP has been available on the NHS in England since 2020. You can access it through any NHS sexual health clinic. You will need to have an HIV test before starting and be confirmed HIV negative. You will also be tested for hepatitis B and your kidney function will be checked, as PrEP can affect kidney health in a small number of people. Regular 3-monthly check-ups are standard while on PrEP.
Does PrEP protect against other STIs?
No — PrEP only prevents HIV. It offers no protection against chlamydia, gonorrhoea, syphilis, herpes, HPV, or other sexually transmitted infections. Because PrEP users often reduce their condom use, rates of other STIs have increased in some PrEP-using communities. Regular STI testing every 3 months is strongly recommended for anyone on PrEP.