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Division of HIV and STD Programs


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Division of HIV and STD Programs
600 S. Commonwealth Ave., 10th Floor
Los Angeles, CA 90005
Phone:(213) 351-8000
Fax: (213) 738-0825
Office Hours: 8 a.m.-5 p.m. M-F
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PEP Information for Patients

What is PEP?

  • Post-Exposure Prophylaxis − is an emergency medication for people who are HIV-negative and may have been exposed to HIV. If you think you were exposed to HIV, go immediately to a clinic or emergency room and ask for PEP.


PEP: The Basics

  • Know Your Risk. PEP can protect you if you had anal or vaginal sex without a condom with someone who has, or might have, HIV. PEP can also prevent HIV if you were exposed while injecting drugs.

  • Act Fast. PEP works best if started right away. Go to an emergency room or clinic as soon as possible and ask about PEP. You should begin PEP no more than 72 hours after exposure.  

  • Take PEP for 28 Days. PEP is taken in pill form for 28 days. You need to take PEP each day to keep enough medicine in your body to stop HIV. If you want to stop taking PEP, talk to your doctor first.

  • Know about Common Side Effects. PEP can have mild side effects, like stomach pain and headache.

  • Be Ready to Follow-Up. After you finish taking PEP, your doctor will give you an HIV test to make sure PEP worked.

  • Find Out about Paying for PEP. Many insurance plans including Medi-Cal cover PEP. Assistance may be available if you are uninsured.

  • Consider PrEP.  f you often worry about exposure to HIV, ask your doctor about PrEP – a daily pill that helps prevent HIV.

How does PEP stop HIV?
  • PEP contains some of the same medicines that people with HIV take to stay healthy. If you are exposed to HIV, it takes a few days for an HIV infection to take hold in your body. As soon as you start PEP, these medicines begin to stop the virus from multiplying. As you continue taking PEP for the full 28–days, cells with HIV die and the virus stops spreading to the rest of your body.

How do I know if I need PEP?
  • If you are HIV-negative, PEP can protect you if you had anal or vaginal sex without a condom (or your condom broke) with someone who has HIV or may have HIV. PEP can stop HIV if you were the victim of sexual assault. PEP can also stop HIV if you were exposed while injecting drugs. 

  • You may be at higher risk of HIV infection if you were the receptive (or “bottom”) partner in anal or vaginal sex (if you had a partner’s penis in your anus or vagina). Receptive partners have a greater chance of exposure to HIV through semen or blood.

  • PEP is NOT usually recommended after sex that has a lower risk of spreading HIV, like oral sex. If you are unsure whether you are at risk of HIV infection, ask a doctor.

  • PEP is only meant to be used for a one-time exposure to HIV. If you often worry about being exposed to HIV, ask your doctor about PrEP – Pre-Exposure Prophylaxis – a daily pill that helps prevent HIV.

How do I take PEP?
  • PEP is prescribed by a doctor or nurse. You should take PEP exactly as prescribed.

  • You should begin PEP no more than 72 hours after exposure.

  • When you start PEP, you may be given a “starter pack” with a few days’ supply of pills. This gives you time to fill a prescription for the rest of the 28 days.

  • PEP is much more effective at stopping HIV if you take all the pills for the full 28 days. It is very important never to skip a dose. It is best to take your pills at the same time every day.

  • PEP involves several steps:

    • Before you start PEP, you will be tested for HIV. Your healthcare provider will also check your kidney and liver function and your overall health.

    • During a follow-up appointment or phone call, your provider will ask you about side effects and HIV risk, and make sure you are taking all the pills in PEP.

    • When you finish PEP, you will be tested again to make sure you have not become infected with HIV.

    • After you finish PEP, stay HIV-negative. Use condoms, and ask your doctor about PrEP. If you inject drugs, always use a clean syringe.

Is PEP safe? What are the side effects?
  • PEP is safe. Emergency PEP has been used for many years to stop HIV in people who were accidentally exposed while at work.

  • PEP can cause mild side effects, including upset stomach and headaches, especially at the beginning of treatment. 

  • If side effects are bothering you, tell your medical provider right away. There may be ways to help you feel better. Do not stop taking PEP before talking to your provider.

How well does PEP work?
  • 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. In one study of healthcare workers who were accidentally exposed to HIV, PEP reduced the rate of infection by 80%.

If I take PEP, do I still have to use condoms?
  • PEP does not provide full protection against HIV. Condoms give you and your partners additional protection, even while on PEP. Condoms also protect against other sexually transmitted infections (STIs) and unintended pregnancy.
  • PEP is for emergency situations. If you worry about regular exposure to HIV through sex or while injecting drugs, PrEP may be a ­­better option for you.

How do I pay for PEP?
  • In LA County, PEP is covered by Medi-Cal and many private health insurance and prescription plans.
What if I don’t have insurance?
How else can I stay HIV-negative?

What is a High-risk HIV Exposure?

  • Having sex or sharing needles with a known HIV-positive partner or a partner of unknown status and one of the following events:

    • Unprotected receptive anal sex or with a failed condom

    • Unprotected insertive anal sex or with a failed condom

    • Unprotected receptive vaginal intercourse or with a failed condom

    • Unprotected insertive vaginal intercourse or with a failed condom

    • Sharing injection drug paraphernalia
Where Can I Get PEP in Los Angeles County?
  • Talk to your regular doctor or nurse or visit one of the many clinics with experience providing PEP in LA County.

  • For more information call the LA County PEP warmline - (213) 351-7699

  • The Los Angeles Gay and Lesbian Center in Hollywood - (323) 860-5855 (Option 4)

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