PEP (Post-Exposure Prophylaxis)

PEP stands for post exposure prophylaxis. PEP is a series of pills you can start taking very soon after you’ve been exposed to HIV that lowers your chances of getting it. But you have to start PEP within 72 hours, or 3 days, after you were exposed to HIV, or it won’t work. The sooner you start, the better it works — every hour matters.

You take PEP 1-2 times a day for at least 28 days. The medicines used in PEP are called antiretroviral medications (ART). These medicines work by stopping HIV from spreading through your body.

How do I get PEP?

You can get PEP from emergency rooms. It might also be available at some health clinics or Planned Parenthood health centers, and some doctors’ offices, but call first to make sure they have PEP in stock. 

You can start PEP up to 72 hours (3 days) after you were exposed to HIV, but don’t wait — it’s really important to start PEP as soon as possible. So if you can’t get to a doctor or nurse right away, go to the emergency room as soon as you can. Every hour counts.

Before you get PEP, the nurse or doctor will talk with you about what happened, to decide whether PEP is right for you. They’ll give you a blood test for HIV (if you already have HIV, you won’t be able to use PEP). You’ll also be tested for Hepatitis B. And if you were exposed to HIV through sex, you’ll get tests for other STDs like gonorrhea, chlamydia, and syphilis.

What happens when I’m on PEP?

PEP isn’t just a one-time pill — it’s a regimen where you take many pills over many weeks. If your nurse or doctor gives you PEP, you’ll need to take medicine 1-2 times a day for at least 28 days (4 weeks). It’s important that you take every pill as directed and don’t skip doses, otherwise PEP may not work as well.

PEP isn’t 100% effective, and it won't prevent future HIV infections like PrEP can. So it’s important to keep protecting yourself and others from HIV while you’re on PEP. Use condoms every time you have sex. If you inject drugs, don’t share needles or works. This helps protect you from being exposed to HIV again. And it lowers the chances of giving HIV to others if you do have it

If you develop symptoms like a fever or rash while using PEP, talk with your doctor. These may be signs of the beginning stages of HIV.

What are the side effects of PEP?

There can be side effects of PEP, like stomach aches and being tired. But PEP side effects aren’t dangerous, and they can be treated. Talk with your nurse or doctor if you have side effects that are really bothering you.

If PEP doesn’t work, you may have symptoms of the first stage of an HIV infection, like a fever or rash. If you have these symptoms while you’re on PEP, or within a month after finishing PEP, call your nurse or doctor.

What happens after I take PEP?

You need to visit your nurse or doctor for follow-up testing after you finish PEP. You’ll get another HIV test 4-6 weeks after you were first exposed to HIV, and then you’ll be tested again 3 months later. Depending on your situation, your doctor may recommend another HIV test 6 months later.

It’s really important to get these follow-up tests to make sure PEP worked. In the meantime, keep protecting yourself and others from HIV by using condoms when you have sex, and not sharing needles or works.