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When people have been at risk of HIV exposure, for example if they have fucked without a condom, there’s a treatment called post-exposure prophylaxis (PEP). This may prevent HIV infection after the virus has entered the body.

  • PEP involves taking anti-HIV drugs for four weeks.
  • It must be started as soon as possible after having sex without a condom or a condom breaking – ideally within 24 hours but definitely within 72 hours (three days).
  • There can be side effects such as diarrhoea, nausea and headaches, but the medication used in PEP has recently been changed and these side effects are now much less common.
  • PEP isn’t guaranteed to work, but is very effective if taken quickly.
  • It’s available from sexual health and HIV clinics and Accident and Emergency (A&E) departments in hospitals, but not from General Practitioners.
  • Eight out of 10 gay men who get HIV get it from someone who didn’t know he had the virus. Even if someone has tested previously, they may have been infected recently and don’t know about it yet. If you have had unprotected sex with a guy and can’t be sure of his HIV status, then you should think about accessing PEP quickly.

Try to avoid using drugs while on your course of PEP as there can be dangerous interactions.
Assess your risk with this short quiz.

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Published: 31/08/2018
Next review: 31/08/2021