If you think you have been exposed to HIV in the last 72 hours (3 days), you should consider PEP. which stands for Post Exposure Prophlaxis.

PEP is a course of HIV medication that you can take if you have been at risk of HIV infection. You will have to take the medication for a month but if you start taking it within 72 hours of being at risk, it may prevent you from becoming infected with HIV.


PEP = a treatment to stop a person becoming infected with HIV after it’s got into their body.

PEP treatment only works if started as soon as possible and definitely within 72 hours of exposure, so act fast!



PEP is a course of anti-HIV medication that should prevent HIV infection after a possible HIV exposure, if taken within 72 hours.

It needs to be taken for 4 weeks after any possible HIV infection and can have side effects which can include; diarrhoea, nausea, and severe headaches.

Post = after
Exposure = a situation where HIV has a chance to get into someone’s bloodstream
Prophylaxis = a treatment to stop any infection happening

PEP will only be given if specialist doctors decide you are at a high risk for HIV infection; if doctors decide you are not at high risk then you will not receive PEP. Caution:

PEP is NOT a substitute for condoms.




If HIV gets into someone’s bloodstream it takes time before the virus permanently infects them. Starting PEP during this short period of time can kill the virus before this happens.

PEP has the best chance of working the sooner it’s begun. Within 24 hours is best but it can be given up to 72 hours (3 days) after possible exposure. The longer the wait, the more chance PEP doesn’t work. After 72 hours PEP is unlikely to work at all so it’s not usually offered. Someone might get it if it’s a few hours after this deadline but not if it’s longer. PEP isn’t guaranteed to work.

Some people take it and, for various reasons, it doesn’t work and they end up HIV positive. This is mostly because they:

  • Wait too long before taking it (starting within 24 hours is best)

  • Don’t take the pills for the full 28 days or exactly how the doctor tells them.




  • St Peter's Health Centre (Sexual health clinic)

  • Loughborough Health Centre

  • Leicester Royal Infirmary A&E department

  • Sexual health clinics (GUM/sexual health clinics)

  • Hospitals (usually A&E or ‘Accident & Emergency’ departments)

  • If you already have HIV try your HIV clinic if the PEP is for someone you’ve had sex with


Not all these places in every part of the country will have PEP or be able to give it.

GPs won’t be able to prescribe PEP.