Frequently Asked Questions

What is PrEP?


Pre-exposure prophylaxis (or PrEP) is a method for people at very high risk for HIV take HIV medicines daily to lower their chances of getting infected. A combination of two HIV medicines (tenofovir and emtricitabine), sold under the name Truvada® (pronounced tru vá duh), is approved for daily use as PrEP to help prevent an HIV-negative person from getting HIV from a sexual or injection-drug-using partner who’s positive. 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. CDC,HIV Basics, PrEP. March 2018




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 infection. 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 20 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. CDC,HIV Basics, PrEP. March 2018.




How well does PrEP work?


Studies have shown that PrEP reduces the risk of getting HIV from sex by more than 90% when used consistently. Among people who inject drugs, PrEP reduces the risk of getting HIV by more than 70% when used consistently. CDC, HIV Basics, PrEP. March 2018




How do I get 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 may also be able to receive PrEP through your local health departments. CDC, HIV Basics, PrEP. March 2018.




How much does PrEP cost?


The cost of PrEP is covered by many health insurance plans, and a commercial medication assistance program provides free PrEP to people with limited income and no insurance to cover PrEP care. CDC, HIV Basics, PrEP. March 2018.




Does PrEP have side effects?


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. CDC, HIV Basics, PrEP. March 2018.