Emergency Post-Exposure Prophylaxis (PEP)

PEP (post-exposure prophylaxis) is emergency medicine that can prevent a new HIV infection.

  • Take emergency PEP if you may have been exposed to HIV
  • Start PEP as soon as possible, and no more than 72 hours after exposure
  • Take PEP pills as prescribed, every day for 28 days

Where to get PEP in NYC

To start emergency PEP right away, call the NYC 24/7 PEP Hotline at 844-3-PEPNYC (844-373-7692).

You can also go to a clinic, emergency room or NYC Sexual Health Clinic and ask for PEP to prevent HIV, or use the NYC Health Map to find an experienced PEP provider.

How to Pay for PEP

Many insurance plans including Medicaid cover emergency PEP. Financial assistance is available.

If you do not have health insurance, see the NYC Health Map for clinics that provide PEP to uninsured people.

Who Should Take PEP

Emergency PEP can protect you if you had anal or vaginal sex or shared drug injection equipment in the past 72 hours with someone who may have HIV.

You do not need PEP if you were using condoms or taking PrEP (pre-exposure prophylaxis), or if your partner is taking HIV treatment and has an undetectable level of HIV. PEP is not usually recommended after sex that has a lower risk of spreading HIV, like oral sex.

How PEP Stops HIV

If you are exposed to HIV, it takes a few days for an HIV infection to take hold in your body. Once you take the first dose, the medicines in emergency PEP stop the virus from multiplying. As you continue taking PEP, cells with HIV die and the virus cannot spread to the rest of your body.

Take the pills in PEP as prescribed, every day for 28 days, to make sure you have enough medicine in your body to prevent an HIV infection.


Emergency PEP is safe and has been used for many years to prevent HIV.

Side Effects

Emergency PEP can cause mild side effects, including upset stomach and headaches. These symptoms often get better or go away after the first week of taking PEP.

If side effects continue to bother you, tell your health care provider right away. There may be ways to help you feel better. Do not stop taking PEP before talking to your provider.


In one study of health care workers who were accidentally exposed to HIV, emergency PEP reduced the rate of infection by 80%. PEP is not 100% effective, but if you take PEP immediately after an exposure and for the full 28 days, it often prevents HIV infection.

After PEP, Consider PrEP

Emergency PEP can prevent HIV after a one-time exposure. If you worry about being exposed to HIV, ask your doctor about taking PrEP to prevent HIV. PrEP is safe and effective medicine available as a daily pill or an injection you receive every two months.

Additional Resources

More Information