Post-exposure prophylaxis

What is post-exposure prophylaxis?
Post-exposure prophylaxis (PEP) for HIV is a treatment that may stop you becoming HIV-positive if you have been exposed to the virus. It should be started as soon as possible after a high-risk exposure and must be started within 72 hours. Evidence suggests PEP may reduce the chances of being infected with HIV by approximately 80 percent.

What is high-risk exposure?
A high-risk exposure to HIV is generally a sexual or needle-stick exposure to the body fluids of a person known to be or highly likely to be infected with HIV. Examples include unprotected vaginal sex with a woman who is HIV positive, unprotected anal sex with a gay or bisexual man of unknown HIV status or sharing drug-injecting equipment with a person who is
HIV positive.

How do I get PEP?
To access PEP at St Mary's Hospital you can come to the walk-in sexual health clinic at the Jefferiss wing. If you need PEP outside of the clinic's opening times, go to your nearest accident and emergency (A&E) department. St Mary's Hospital and Charing Cross Hospital both have general A&E departments - for more information see our In an emergency section.

How do I take PEP?
PEP should be started as soon as possible after a high-risk exposure and must be started within 72 hours. It needs to be taken for one month.