PrEP (Pre-Exposure Prophylaxis)


Welcome to the County of San Diego Pre-Exposure Prophylaxis (PrEP) web page. PrEP is an effective HIV prevention strategy that can help end the HIV epidemic in the United States (U.S.). The U.S. Food and Drug Administration approved the first daily oral PrEP medication in 2012 and there are now oral and injectable PrEP medication options. On this web page, frequently asked questions about PrEP, how to request additional information, and links to clinical services offered through the County of San Diego Sexual Health Clinics can be found.


If you think that you may have been exposed to HIV from sex or a needle-sharing partner within the last 72 hours (3 days), visit our HIV Post-Exposure Prophylaxis (PEP) web page for more information on PEP. 

What is PrEP?

  • PrEP, or pre-exposure prophylaxis, is medicine for people who are HIV-negative to reduce the chances of getting HIV from sex or injection drug use. When taken as prescribed, and combined with other HIV prevention services, PrEP is highly effective for preventing HIV.
  • Currently, there are two FDA approved daily oral medications and one long-acting injectable form of PrEP.

Frequently Asked Questions (FAQs) 

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  • What is PrEP?

    PrEP, or pre-exposure prophylaxis, is medicine for people who are HIV-negative to reduce the chances of getting HIV from sex or injection drug use. 

  • Is PrEP right for me?

    PrEP may benefit you if you test negative for HIV and any of the following apply to you:

    • You have had anal or vaginal sex in the past 6 months, and you have a sexual partner with HIV, have not consistently used a condom, or have been diagnosed with a sexually transmitted infection in the past 6 months.
    • You inject drugs and you have an injection partner with HIV, or share needles, syringes, or other drug injection equipment.
    • You have been prescribed PEP (post-exposure prophylaxis) and have used multiple courses of PEP.

    You may choose to take PrEP, even if the above does not apply. Talk to your health care provider to learn more.

  • How effective is PrEP?

    PrEP reduces the risk of getting HIV from sex by about 99% when taken as prescribed.

  • How long does PrEP take to work?

    For receptive anal sex (bottoming), PrEP pills reach maximum protection from HIV at about 7 days of daily use. For receptive vaginal sex and injection drug use, PrEP pills reach maximum protection at about 21 days of daily use.

  • Is PrEP safe and does PrEP have side effects?

    PrEP is safe. Some people may have side effects, such as nausea, diarrhea, fatigue, or headache. These side effects usually go away over time. Talk to your healthcare provider if any side effects do not go away or you have any questions.

  • Is PrEP covered by my insurance?

    In most cases, yes! Most insurance plans and state Medicaid programs cover PrEP. Under the Affordable Care Act, PrEP must be free under almost all health insurance plans. To find out whether your health plan covers PrEP medications without charge, check with your insurance company or health care plan. 

  • What if I do not have health coverage?

    There are resources that may be able to help pay for PrEP and your necessary clinic visits and tests.

    • Co-pay assistance programs.


  • What else can I do to protect myself from HIV?

    Many factors can decrease someone’s chance of getting or transmitting HIV. Abstinence (not having sex) can prevent getting HIV from a sex partner. Taking medicine to prevent HIV and using condoms can protect you and your partners from HIV, People living with HIV taking antiretroviral therapy as prescribed and keeping an undetectable viral load cannot transmit HIV through sex (Undetectable = Untransmittable or U=U or treatment as prevention).

    Get tested for HIV and encourage partners to get tested too.

  • How can I start PrEP?

    PrEP assistance can be provided through a County of San Diego Sexual Health Clinic or by referral depending on which PrEP medication option you are interested in. Call our PrEP navigator/coordinator for more information at (619) 409-3053 or complete the request for more information link below. You can also send an e-mail for more information.



Understanding HIV and PrEP Through Images


For more information,
call (619) 409-3053 or e-mail our PrEP Navigator.


Last updated April 8, 2024