Glossary /
PEP (Post-Exposure Prophylaxis)
FormalPEP · post-exposure prophylaxis
Emergency medication after possible HIV exposure — the sooner the better, and it must start within 72 hours.
PEP stands for post-exposure prophylaxis. It is emergency medication used after a possible exposure to HIV — for example sex without protection, a broken condom, or a needle accident — to stop the virus before it can establish itself in the body.
Timing is everything: PEP must start as soon as possible after the exposure, and no later than 72 hours — the earlier the better. It is then taken as prescribed for a full course, usually around four weeks. If you are worried an exposure just happened, this is urgent but manageable: contact a local infectious-disease clinic, sexual-health service, or HIV service as quickly as you can. For more immediate directions, see Get help now.
Register note: PEP is a neutral clinical term. Seeking it is not shameful — it is taking responsible care of yourself.
Common misreading: first, treating it as routine protection — PEP is a one-off emergency measure; anyone needing ongoing prevention should look into PrEP. Second, assuming “a few days later is fine” — miss the 72-hour window and its effectiveness drops sharply. After a course, follow-up testing is still needed at the right point in the window period.