PrEP

Pre-exposure prophylaxis (or PrEP) is when people at risk for HIV take daily medicine to prevent HIV. PrEP can stop HIV from taking hold and spreading throughout your body. When taken daily, PrEP is highly effective for preventing HIV from sex or injection drug use. PrEP is much less effective when it is not taken consistently.

Studies have shown that PrEP reduces the risk of getting HIV from sex by about 99% when taken daily. Among people who inject drugs, PrEP reduces the risk of getting HIV by at least 74% when taken daily.

Video Introduction to PrEP

What is PrEP? A Brief Intro

Protect yourself. Learn about PrEP (Pre-Exposure Prophylaxis) and how it works in this short video.

What is PrEP?

Pre-exposure prophylaxis (or PrEP) is when people at risk for HIV take daily medicine to lower their chances of getting HIV. Two medications, sold under the brand names Truvada® and Descovy® are approved for daily use as PrEP to help prevent a person without HIV from getting the virus from sex or injection drug use. Studies have shown that PrEP is highly effective for preventing HIV if it is used as prescribed. PrEP is much less effective when it is not taken consistently.

Note: Truvada® for PrEP is recommended to prevent HIV for all people at risk through sex or injection drug use. Descovy® for PrEP is recommended to prevent HIV for people at risk through sex, excluding people at risk through receptive vaginal sex. Descovy has not yet been studied for HIV prevention for receptive vaginal sex, so it may not be appropriate for some people.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

Why take PrEP?

For those at risk for HIV, daily PrEP is highly effective for preventing HIV from sex or injection drug use. PrEP is much less effective when it is not taken consistently. See How well does PrEP work?

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

Is PrEP a vaccine?

No. PrEP does not work the same way as a vaccine. A vaccine teaches your body to fight off infection for several years. For PrEP, you take a pill every day by mouth. If you take PrEP daily, the presence of the medicine in your bloodstream can often stop HIV from taking hold and spreading in your body. If you do not take PrEP every day, there may not be enough medicine in your bloodstream to block the virus.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

Should I consider taking PrEP?

PrEP is for people without HIV who are at risk for getting the virus from sex or injection drug use. The federal guidelines recommend that PrEP be considered for people who are HIV-negative who:

Have had anal or vaginal sex in the past 6 months and:

  • Have a sexual partner with HIV (especially if the partner has an unknown or detectable viral load)
    or
  • Have not consistently used a condom
    or
  • Have been diagnosed with an STD in the past 6 months

PrEP is also recommended for people who inject drugs and

  • have an injection partner with HIV
    or
  • share needles, syringes, or other equipment to inject drugs (for example, cookers).

PrEP should also be considered for people who have been prescribed non-occupational post-exposure prophylaxis (PEP) and

  • report continued risk behavior, or
  • have used multiple courses of PEP.

If you have a partner with HIV and are considering getting pregnant, talk to your doctor about PrEP if you’re not already taking it. PrEP may be an option to help protect you and your baby from getting HIV while you try to get pregnant, during pregnancy, or while breastfeeding.

Because PrEP involves daily medication and regular visits to a health care provider, it may not be right for everyone. And PrEP may cause side effects like nausea in some people, but these generally subside over time. These side effects aren’t life threatening. See Is PrEP safe?

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

How well does PrEP work?

Studies have shown that PrEP reduces the risk of getting HIV from sex by about 99% when taken consistently. Among people who inject drugs, PrEP reduces the risk of getting HIV by at least 74% when taken consistently. Since PrEP does not protect against other STDs, use condoms the right way every time you have sex.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

Is PrEP safe?

PrEP can cause side effects like nausea in some people, but these generally subside over time. No serious side effects have been observed, and these side effects aren’t life threatening. If you are taking PrEP, tell your health care provider about any side effects that are severe or do not go away.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

I’m transgender, will PrEP interfere with my hormone therapy?

More studies are needed on this topic. But there are no known drug conflicts or interactions between the medicines used in PrEP and hormone therapy. There is no known scientific reason why the drugs cannot be taken at the same time. If you are worried that PrEP will affect your hormone therapy, ask your health care provider to check your hormone levels. People who use PrEP should see their health care provider every 3 months for follow up, HIV tests, and to have their prescriptions refilled. This visit could be combined with your hormone therapy appointments.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

How can I start PrEP?

PrEP can be prescribed only by a health care provider, so talk to yours to find out if PrEP is the right HIV prevention strategy for you. You must take PrEP daily for it to work. Also, you must take an HIV test before beginning PrEP to be sure you don’t already have HIV and every 3 months while you’re taking it, so you’ll have to visit your health care provider for regular follow-ups.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

How do I speak to my doctor or other health care provider about PrEP?

Please see the brochure Talk to Your Doctor About PrEP in English pdf icon[PDF – 299 KB] and Spanish pdf icon[PDF – 675 KB], which has some questions you should ask your health care provider when discussing whether PrEP (taking daily HIV medicines) is right for you.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

How can I get help to pay for PrEP?

Most insurance plans and state Medicaid programs cover PrEP. Prior authorization may be required.

Free medication program: There are medication assistance programs that provide free PrEP medications to people with no insurance to cover PrEP care. To learn more, call 855-447-8410 or visit www.getyourprep.comexternal icon

Co-pay assistance program: Income is not a factor in eligibility. More information is available at: https://www.gileadadvancingaccess.comexternal icon

Some states have their own PrEP assistance programs.  Some cover medication, some cover clinical visit and lab costs, some cover both.  To learn more visit: https://www.nastad.org/prepcost-resources/prep-assistance-programsexternal icon

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

If I take PrEP, can I stop using condoms when I have sex?

No, you should not stop using condoms because you are taking PrEP. PrEP doesn’t give you any protection against other STDs, like gonorrhea and chlamydia.

If used the right way every time you have sex, condoms are highly effective in preventing HIV and some STDs you can get through body fluids, like gonorrhea and chlamydia. However, they provide less protection against STDs spread through skin-to-skin contact, like human papillomavirus or HPV (genital warts), genital herpes, and syphilis.

See How well do condoms prevent HIV?

Learn the right way to use a male condom.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

How long do I need to take PrEP?

You must take PrEP daily for it to work. But there are several reasons people stop taking PrEP. For example,

  • If your risk of getting HIV infection becomes low because of changes in your life, you may want to stop taking PrEP.
  • If you find you don’t want to take a pill every day or often forget to take your pills, other ways of protecting yourself from HIV infection may work better for you.
  • If you have side effects from the medicine that are interfering with your life, or if blood tests show that your body is reacting to PrEP in unsafe ways, your provider may stop prescribing PrEP for you.

You should discuss this question with your health care provider.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

How long do I have to take PrEP before it is effective?

When taken every day, PrEP is safe and highly effective in preventing HIV. PrEP reaches maximum protection from HIV for receptive anal sex at about 7 days of daily use. For receptive vaginal sex and injection drug use, PrEP reaches maximum protection at about 21 days of daily use. No data are yet available about how long it takes to reach maximum protection for insertive anal or insertive vaginal sex.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

Does taking PrEP long-term have harmful health effects?

In people without HIV and have taken PrEP for up to 5 years, no significant health effects have been seen.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

Can you start PrEP after you have been exposed to HIV?

PrEP (pre-exposure prophylaxis) is only for people who are at risk of getting HIV. But PEP (post-exposure prophylaxis) is an option for someone who thinks they’ve recently been exposed to HIV during sex or through injection drug use.

PEP means taking antiretroviral medicines after a potential exposure to HIV to prevent getting the virus. PEP must be started within 72 hours of possible exposure to HIV. If you’re prescribed PEP, you’ll need to take it once or twice daily for 28 days. See our PEP Q&As for more information.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).

How can I locate PrEP in my area?

Visit the PrEP Locator to find a PrEP provider near you.

Where can I find resources about PrEP?

Visit the CDC PrEP resources page for infographics, videos, fact sheets, reports, and other educational materials about PrEP, including resources for health care providers.

Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA).