What is PEP?

PEP stands for Post Exposure Prophylaxis, it's a treatment that may prevent HIV infection after the virus has entered the body.

Here's some things to consider when you're thinking about PEP:-

• It could stop someone getting HIV
• It involves taking anti-HIV drugs for 4 weeks
• It must be started as soon as possible after unsafe sex or a condom not working – and definitely within 72 hours (3 days)
• There are side effects
• PEP isn’t guaranteed to work

PEP is a course of anti-HIV medication that needs to be taken daily over the course of a month. The drugs have been available for HIV prevention since the early- to mid-1990s for health workers who have had 'needle-stick' or similar injuries.

More recently, PEP has been made available under strict prescribing guidelines to people who might have been exposed to HIV during sex. If you think you might have exposed yourself to HIV during sex it might be worth thinking a bit more about how HIV is transmitted - there's more information in our risk assessment here.

For the treatment to be effective, it needs to be started within 72 hours of exposure. It can cause severe side effects such as diarrhoea, nausea and prolonged headaches.

PEP can be available from sexual health clinics and hospital accident and emergency departments. Many people say they have had difficulty obtaining PEP from these places, especially outside metropolitan areas. You are more likely to be successful if you enquire at a sexual health clinic or A&E in a hospital where there is also a specialist HIV clinic.

You must also meet the prescribing guidelines for PEP - to find out if you are likely to meet the criteria, use our online self-assessment tool.

PEP is not a cure for HIV and is not guaranteed to prevent HIV from taking hold once the virus has entered the body. Condoms and lube for sex remain the most efficient way of staying safe from HIV.