What to know first
Emergency HIV prevention after a possible exposure
- Seek care immediately if the exposure was within 72 hours.
- PEP is taken for 28 days with follow-up testing.
- If exposures recur, discuss transitioning to PrEP after PEP.
What is PEP?
PEP, or Post-Exposure Prophylaxis, is an emergency HIV prevention treatment. It involves taking antiretroviral medication after potential exposure to HIV—such as through unprotected sex or sharing needles.
PEP must be started within 72 hours after potential exposure.
When Should You Consider PEP?
If you believe you've recently been at risk of HIV infection—such as:
- Having unprotected sex or experiencing condom failure
- Sharing needles or injection equipment
- Being sexually assaulted
Seek care immediately, ideally within 24 hours and no later than 72 hours (3 days). The sooner PEP is started, the more effective it is—every hour counts. If prescribed, PEP must be taken as prescribed for a full 28-day course; the dosing schedule depends on the regimen.
PEP Is for Emergency Use Only
PEP is intended for emergency situations after potential exposure to HIV. It is not meant for daily or routine use.
- PEP is not a substitute for condoms or PrEP (Pre-Exposure Prophylaxis).
- Ongoing exposure does not rule out emergency PEP for a recent exposure. A provider can assess PEP now and plan PrEP afterwards.
- If you are regularly at risk, you should speak with a healthcare provider about using PrEP, which is more appropriate for long-term prevention.
How Much Does PEP Cost?
Contact a hospital emergency department or a clinic that can assess PEP immediately. Do not wait for a routine online appointment or for symptoms. Tell the provider when the exposure happened and about medicines you use.
Ask the service about costs and coverage for assessment, medicine and follow-up tests. There is no single price for all clinics, and checking prices should not delay urgent assessment.
It's recommended to call ahead for details. You can find nearby clinics or hospitals that provide HIV testing and PEP services for urgent care here.
Should I still seek care after 72 hours?
Yes. PEP is generally not recommended after 72 hours, but a provider can still plan HIV testing, assess other health needs and discuss future prevention. If you are unsure of the time, explain the possible range rather than deciding that care is unnecessary.
Do I need follow-up after completing PEP?
Yes. Completing the course does not replace follow-up testing. Contact the prescriber about side effects or missed doses and tell them about any new exposure. Keep using the agreed prevention plan during follow-up, including a planned transition to PrEP when appropriate.
Timeline after a possible exposure
Do not wait for symptoms or a later test before seeking PEP assessment; timing matters.
| Time | What to do |
|---|---|
| Immediately–72 hours | Contact a provider for exposure assessment, baseline testing and prompt treatment if indicated |
| For 28 days | Take medicine as prescribed and contact the care team about side effects |
| After starting | Complete follow-up testing and plan ongoing prevention |