Is HIV PEP (Post-Exposure Prophylaxis) Recommended for Me?

Medically Reviewed on 12/6/2021

If you have been exposed to HIV recently

If you are human immunodeficiency virus (HIV)-negative and have been exposed to HIV recently, you should immediately consult a physician. Your physician may prescribe post-exposure prophylaxis (PEP) to help prevent becoming infected with HIV. You can be exposed to HIV if you:

  • Had sex with an HIV-positive person.
  • Shared intravenous needles or drug preparation equipment.
  • Were sexually assaulted.
  • Are a health worker who got a needle prick while working with HIV-positive people.

What is post-exposure prophylaxis?

Post-exposure prophylaxis (PEP) refers to a short course of antiretroviral medications taken soon after a possible exposure to HIV to prevent the virus from infecting your body. You must start PEP within 72 hours (three days) after being exposed to HIV; the earlier, the better. PEP can reduce the risk of HIV infection by 80 percent if you take it as prescribed by your doctor.

When should I start PEP?

Post-exposure prophylaxis (PEP) must be started within 72 hours (three days) after exposure to human immunodeficiency virus (HIV). The earlier you start, the better it works to prevent HIV infection.

You need to take PEP medication every day for 28 days. While taking medicines, you need to follow up with your physician for HIV screening and other tests.

How does PEP work?

Post-exposure prophylaxis (PEP) medicines are antiretroviral drugs that treat human immunodeficiency virus (HIV) infection. They are a combination of three drugs that are taken once or twice a day for 28 days. The most commonly used combination drugs are as follows:

Some of the guidelines followed for giving PEP include:

  • For adults, the Centers for Disease Control and Prevention (CDC) recommends a combination of three antiretroviral drugs.
  • Women who are pregnant, or who could become pregnant while on PEP should reveal this information to their doctor so that medication can be prescribed to avoid the risk of congenital birth defects.
  • Children over the age of two are eligible for PEP if they have been exposed to HIV.

While taking PEP, you should use condoms when you have sexual intercourse to lower the risk of infecting your partner with HIV. If you get HIV even after taking PEP, it might be due to development of viral resistance to some of the medications.

What happens when I am on PEP?

Post-exposure prophylaxis (PEP) is taken once or twice a day for 28 days (four weeks). You must take every pill as directed and never skip doses in order for PEP to be effective. PEP isn’t 100 percent effective and won’t prevent future human immunodeficiency virus (HIV) infections if you have another exposure to HIV. If you fall under the high-risk category, you should talk to your doctor about taking pre-exposure prophylaxis (PrEP) to receive maximum protection. Moreover, to stay safe from HIV infections, you should:

  • Use condoms every time you have sex.
  • Avoid sharing intravenous needles or works/equipment for drug use.
  • Take necessary precautions if you are a health worker.

What are the side effects of PEP?

Some of the mild side effects of post-exposure prophylaxis (PEP) include:

In rare cases, PEP can cause severe health issues including liver disease and flu-like symptoms.  If you experience any unusual changes in your health while taking PEP, consult your doctor immediately.


A Timeline of the HIV/AIDS Pandemic See Slideshow
Medically Reviewed on 12/6/2021
WebMD: "Post-Exposure Prophylaxis (PEP)"

Planned Parenthood: "What is PEP?"

MedLinePlus: "HIV: PrEP and PEP"