HIV PEP: What to Do in the First 72 Hours After an Exposure

If you think you may have been exposed to HIV in the last few days, time matters more than anything else on this page. Read the first section, then go and get care. You can come back and finish reading afterwards.

What should I do right now if I think I was exposed to HIV?

Go to an emergency room or an urgent care clinic today, or see your health care provider right away. Say: “I may have been exposed to HIV and I’d like to be assessed for PEP.”

PEP (post-exposure prophylaxis) is medicine that prevents HIV after a possible exposure. The CDC says it must be started within 72 hours (3 days), and that the sooner you start, the better. Its guidance for clinicians describes an exposure to HIV as a medical emergency, because HIV can establish infection very quickly, often within 24 to 36 hours.

• Don’t wait to see if symptoms appear. Some people with early HIV have no symptoms at all.
• Don’t wait for your regular doctor’s next appointment.
• If a clinic can’t see you today, go to an emergency room.

Who should ask about PEP?

The CDC says to talk to a health care provider, an emergency room doctor or an urgent care provider right away if you think you were recently exposed to HIV:

• during sex, for example if a condom broke
• by sharing needles, syringes or other equipment to inject drugs
• if you were sexually assaulted

Clinicians look at whether body fluids from a person who has or might have HIV came into contact with your vagina, penis, rectum, eye, mouth or other mucous membrane, or with broken skin, or if you had a needle-stick. If this happened at work, report it to the right person there and get medical care immediately.

Where can I get PEP?

• An emergency room. Emergency doctors are among the most frequent prescribers of PEP.
• An urgent care clinic. The CDC lists urgent care alongside the ER.
• Your own health care provider. Any licensed prescriber can prescribe PEP.

The CDC’s PEP page has a locator for finding PEP services near you.

What happens when I ask for PEP?

A clinician will usually do an HIV test first, to check you don’t already have HIV. The CDC says not to delay the first dose while waiting for results. If the test shows you already have HIV, PEP is not started, and the clinician will talk with you about HIV care instead.

You may also be offered a pregnancy test, blood tests, and testing for other STIs and hepatitis. A clinician chooses the medicines that suit you. You take them every day for 28 days.

PEP is considered safe. It can cause side effects such as nausea, which in almost all cases can be treated and aren’t life-threatening. If side effects are hard to cope with, call the prescriber rather than stopping on your own. They can often switch the medicine.

What if it has been more than 72 hours?

The CDC does not recommend PEP when more than 72 hours have passed, because it is unlikely to work after that. This can be frightening to read, and it doesn’t mean you have HIV.

Please still get tested by ordering an HIV test online. Our window periods guide explains how soon different HIV tests can pick up an infection, and why a test soon after an exposure may need repeating.

What if I was sexually assaulted?

Seek medical care as soon as you can, and within 72 hours if possible, so that PEP is an option. An emergency room is a good place to start. The CDC’s PEP guidance includes specific considerations for people who have been sexually assaulted, and says you may qualify for partial or total reimbursement of medicine and clinical care costs. What happened is not your fault.

What follow-up testing will I need?

If you take PEP, the CDC says follow-up HIV testing is done at 4 to 6 weeks and again at 12 weeks. Your prescriber will arrange these, and you can also order an HIV test online. During those 12 weeks, the CDC suggests using condoms consistently, avoiding pregnancy or breastfeeding, not sharing needles, and not donating blood, plasma, organs, tissue or sperm.

Is PEP the same as PrEP?

No. PrEP is taken before possible exposures to lower your risk. PEP is an emergency treatment taken after one. People who use PrEP as prescribed typically don’t need PEP, but tell the clinician if you missed doses or only just started. If you may be exposed to HIV again, ask about PrEP. The CDC says no gap is needed between finishing PEP and starting PrEP. You can read more in our PrEP guide.

If you’re also wondering about symptoms, see early HIV symptoms. Symptoms can’t tell you whether PEP is needed, so don’t use them to decide.