PEP stands for post-exposure prophylaxis. It is a short course of HIV medicines used after a possible exposure, when a clinician decides it is appropriate. It is time-sensitive: PEP needs to be started within 72 hours, and sooner is better.

When to seek an urgent assessment

Contact a clinician promptly after a possible exposure involving sex, shared injection equipment, sexual assault or another situation where HIV could be transmitted. The clinician will assess the details of the exposure, not simply the word “exposure.” They may ask about the timing, body sites involved, barrier use, known information about the other person and your current medications.

PEP is not the same as an HIV test

Testing is part of PEP care, but a test cannot replace a timely PEP assessment in the first 72 hours. If PEP is prescribed, it is usually taken daily for 28 days, with follow-up arranged by the treating clinician. Testing may also be repeated at recommended intervals.

What if more than 72 hours have passed?

PEP is generally not recommended after that window. Testing, tailored follow-up and a discussion about future prevention can still be useful. A clinician can help you understand the relevant testing timeline and whether PrEP may be a better ongoing option.

Prepare a short timeline

Write down the date and time, what happened, any condom or barrier use, and whether there have been other recent exposures. This makes an urgent conversation easier and helps the clinician make a prompt, informed decision.

Further reading: Clinical information from CDC or WHO. This guide is general information and does not replace an individual medical assessment.