When it comes to HIV prevention, timing is everything. If you think you’ve been exposed to HIV—through sex, sexual assault, or sharing needles—you may still be able to prevent infection. But you have to move fast.
That’s where PEP (Post-Exposure Prophylaxis) comes in.
PEP is a powerful HIV prevention medication you take after a possible exposure. The catch? You must start it within 72 hours.
What is PEP?
PEP is a 28-day course of antiretroviral medication that can stop HIV from taking hold in your body. It’s an emergency tool, not an everyday prevention method like PrEP. PEP can be life-changing, but only if started within three days of exposure—and ideally, the sooner, the better.
When Should You Use PEP?
You may want to seek PEP if:
- You had unprotected sex (or the condom broke) with someone who may have HIV
- You were sexually assaulted
- You shared needles or injection equipment
- You’re a healthcare worker with a needlestick injury or other high-risk exposure
If any of these happened within the last 72 hours, don’t wait. Go to an emergency room, urgent care, or contact a sexual health provider immediately.
How Does PEP Work?
PEP works by attacking the virus before it can multiply. You take the first dose as soon as possible, then continue the medication daily for 28 days. If taken correctly and on time, PEP can reduce the chance of HIV infection by up to 80% or more.
You will need follow-up testing after finishing PEP to confirm you remain HIV-negative. During this time, use condoms and avoid sharing needles.
Where to Get PEP in St. Louis
At Health Stop STL, we can help connect you to PEP quickly and confidentially. We understand how overwhelming it can feel, and our team is here to support you with compassion and urgency. We also offer:
- Free or low-cost HIV testing
- Rapid STI screening
- PrEP consultations (for ongoing prevention)
- Emergency support for survivors of assault
If you’re unsure where to start, visit Health Stop STL or call us for help navigating your next steps.
PEP Is Not PrEP: Know the Difference
PEP is for emergencies. PrEP (Pre-Exposure Prophylaxis) is a daily or long-acting prevention option for people who may be at ongoing risk. If you find yourself needing PEP more than once, talk to us about transitioning to PrEP. It’s one of the most effective tools available for long-term HIV prevention.
Step Into Your Power
Needing PEP does not mean you’ve failed. It means you’re taking control of your health when it matters most. Whether it’s after a high-risk encounter, sexual assault, or a broken condom, you deserve judgment-free care.
If you think you might need PEP, don’t wait.
Act fast. Get help. Stay protected.
Resources:
Visit Health Stop STL’s Testing & Referral Centerhttps://www.stlouis-mo.gov/government/departments/health/communicable-disease/health-stop-testing-referral-center.cfm for guidance
Call your local emergency department or urgent care
Learn more about HIV prevention at cdc.gov/hiv
You have 72 hours. We’re here for you.
