Frequently Asked Questions about PrEP

How does PrEP stop HIV?

PrEP contains the same medicines that people with HIV use to stay healthy. If you are exposed to HIV, these medicines can stop the virus from multiplying and spreading throughout your body. PrEP only works if you have enough medicine in your body, so you need to take PrEP every day.

Should I consider taking PrEP?

PrEP is for people who are HIV-negative, have a high risk of being exposed to HIV through sex or drug injection, and are ready to take a daily pill. Studies have shown that PrEP works for sexually-active gay and bisexual men, heterosexual women and men, and injection drug users; and is also likely to benefit transgender women. PrEP can help protect anyone whose partner has HIV.

How do I take PrEP?


PrEP is prescribed by a doctor or nurse. You should take PrEP exactly as prescribed. With PrEP, you take a pill once a day, even on the days you don’t have sex or inject drugs. The only medication currently approved for PrEP is Truvada®, a combination pill that contains two different medicines: emtricitabine (Emtriva®) and tenofovir (Viread®). PrEP only works if you are HIV-negative.

Before you start PrEP, you take an HIV test to make sure that you do not have HIV. You also have a check-up to make sure your kidneys and liver are healthy. While you are on PrEP, your doctor or nurse will test you regularly for HIV and other sexually transmitted infections. They will also ask you about your HIV risk and whether you are taking PrEP every day.

PrEP can help you stay HIV-negative when your risk of HIV exposure is high. You may decide to stop taking this medication if your risk changes. But do not stop taking PrEP without first talking to your doctor. Also, tell your doctor if you are thinking about becoming pregnant or if you become pregnant while on PrEP.

Is PrEP safe? What are the side effects?

PrEP is safe. The pill used for PrEP, Truvada®, has been used to treat people with HIV since 2004. PrEP can cause mild side effects, including upset stomach, headaches and weight loss, especially at the beginning of treatment. Rare side effects include kidney or bone problems. Your doctor or nurse can help if side effects are bothering you.

How well does PrEP work?

PrEP is not 100% effective. You can still get HIV, especially if you do not have not enough medicine in your body. In different studies, people taking PrEP were 44% to 75% less likely to get HIV than comparison groups, and people who took PrEP consistently were up to 92% less likely to get HIV.

Can I take PrEP only on the days when I have sex?

No. You must take PrEP every day to keep enough medicine in your body to protect you from HIV.

If I take PrEP, do I still have to use condoms?

PrEP does not provide 100% protection against HIV. Condoms provide additional protection against HIV, even while you take PrEP. Condoms also protect against other sexually transmitted infections and prevent unintended pregnancy. For greater protection against HIV, combine PrEP with other ways to reduce HIV risk.

  • Use condoms.
  • Choose kinds of sex with less risk of spreading HIV, like oral sex.
  • Get tested with your partners for HIV and other sexually transmitted infections.
  • Encourage partners living with HIV to take their medications every day.
  • If alcohol or drugs are a problem, get help.
  • If you inject drugs, always use a clean needle and syringes.
How do I talk with my provider about PrEP?

PrEP is a new medical option to help prevent HIV infection. Because it is a medical intervention, people interested in having PrEP prescribed must have a conversation with their medical provider or with a medical provider at a PrEP clinic. If you’re unsure how to begin the conversation with your provider about PrEP, check out this guide.

How do I pay for PrEP?

Since PrEP is a medical intervention requiring a prescription, most insurances will pay for PrEP. Your PrEP provider may know of additional resources to help. Gilead’s may be able to provide payment assistance for Truvada for PrEP. To apply for Gilead assistance call 1-855-330-5479, Monday through Friday between 9:00 a.m. and 8:00 p.m. (Eastern).