What is Pre-Exposure Prophylaxis (PrEP)?
“PrEP” stands for Pre-Exposure Prophylaxis. PrEP is a way for people who don’t have HIV but who are at very high risk of getting it to prevent HIV infection by taking a pill every day. The pill contains two medicines that are also used to treat HIV. If you take PrEP and are exposed to HIV through sex or injection drug use, these medicines can work to keep the virus from taking hold in your body.
PrEP is a powerful HIV prevention tool and can be combined with condoms and other prevention methods to provide even greater protection than when used alone. But people who use PrEP must commit to taking the drug every day and seeing their health care provider for follow-up every 3 months.
Can Anyone Use PrEP?
PrEP is not for everyone. Federal guidelines recommend that PrEP be considered for people who are HIV-negative and at very high risk for HIV infection. This includes anyone who is in an ongoing relationship with an HIV-positive partner. It also includes anyone who:
- Is not in a mutually monogamous* relationship with a partner who recently tested HIV-negative, and
- Is a
- gay or bisexual man who has had anal sex without a condom or been diagnosed with a sexually transmitted infection within the past 6 months;
- man who has sex with both men and women;
- heterosexual man or woman who does not regularly use condoms during sex with partners of unknown HIV status who are at substantial risk of HIV infection (e.g., people who inject drugs or women who have bisexual male partners).
How Well Does PrEP Work?
When taken every day, PrEP has been shown to reduce the risk of HIV infection in people who are at high risk by more than 90%. PrEP is much less effective if it is not taken consistently. PrEP can be even more effective if it is combined with other ways to prevent new HIV infections like condom use, drug abuse treatment, and treatment for people living with HIV to reduce the chance of passing the virus to others.
PrEP was tested in several large studies with men who have sex with men, men who have sex with women, women who have sex with men, and people who inject drugs. Information on the details of these studies can be found at www.cdc.gov/hiv/prep.
Is PrEP Safe?
Some people in clinical studies of PrEP had early side effects such as an upset stomach or loss of appetite, but these were mild and usually went away within the first month. Some people also had a mild headache. No serious side effects were observed. If you are on PrEP, you should tell your healthcare provider if these or other symptoms become severe or do not go away.