PrEP protects all men against HIV when taken correctly.

PrEP protects all men – including trans men – against HIV when taken correctly.

When PrEP might benefit you:

PrEP will not be the best choice for everyone but it is worth thinking about if:

  • condoms are not easy to use or not always used when you have sex
  • you’ve recently had rectal or front hole sexually transmitted infection (STI)
  • you’ve recently had PEP (post-exposure prophylaxis)
  • you have sex with people whose HIV status you don’t know
  • you have sex with people who are HIV positive but not known to be virally supressed/undetectable
  • you have sex with people from communities that are disproportionately impacted by HIV, or in cities or countries outside the UK where HIV affects a high proportion of the population.

You do not need PrEP if your only sexual partner is HIV positive with a undetectable viral load. They cannot pass on the virus even without condoms.

Understanding your risk

Insertive partner sex carries a much lower risk of contracting HIV.

Starting PrEP: how long it takes for PrEP to protect you from HIV

If you are having receptive anal sex, 2 pills taken 2 to 24 hours before sex will protect you.

This dose will protect:

  • cis men having insertive (top) or receptive (bottom) sex
  • trans men having receptive anal sex only.

PrEP reaches protective levels more quickly in some parts of the body than others.

For PrEP to reach maximum levels of protection in all areas of your body, you need to take a pill every day for 7 days.

More information on starting and taking PrEP.

Stopping PrEP – temporarily or permanently

You can decide to stop taking PrEP whenever you want. But don’t just stop taking the pills on the day you decide.

This dose will protect:

  • cis men — take a daily dose until you have had 2 sex free days.
  • trans men having front hole sex — take a daily dose of PrEP for 7 days after your last risk of exposure to HIV – condomless sex, for example.

Starting PrEP again or using PrEP On Demand

You can choose to start taking PrEP again whenever you want.

You will need:

  • an HIV test if you’ve had a risk of exposure – condomless sex for example – since stopping PrEP

PrEP and STIs

You need to take other precautions, such as using condoms, to help prevent all sexually transmitted infections (STIs) other than HIV.

Information about how vaccinations can prevent some STIs.