HIV Prevention

  • Table of Contents  Table of Contents

Need Help?

  • Call 1-800-448-0440
  • (1 p.m. to 4 p.m. ET)
  • Send us an email

Pre-Exposure Prophylaxis (PrEP)

Last Reviewed: November 7, 2018

Key Points

  • Pre-exposure prophylaxis (PrEP) can help prevent HIV infection in people who don’t have HIV but who are at high risk of becoming infected with HIV.
  • PrEP involves taking an HIV medicine called Truvada every day. PrEP is most effective when taken consistently each day.
  • According to the Centers for Disease Control and Prevention (CDC), by taking PrEP every day, a person can lower their risk of getting HIV from sex by more than 90% and from injection drug use by more than 70%.

What is PrEP?

PrEP stands for “pre-exposure prophylaxis.” The word “prophylaxis” means to prevent or protect from an infection or disease.

PrEP can help prevent HIV infection in people who don’t have HIV but who are at high risk of becoming infected with HIV. PrEP involves taking an HIV medicine called Truvada every day. Truvada contains two HIV medicines (tenofovir disoproxil fumarate and emtricitabine) combined in one pill. If a person is exposed to HIV, having the PrEP medicine in the bloodstream can stop HIV from taking hold and spreading throughout the body.

Who should consider taking PrEP?

PrEP is for people who don’t have HIV but who are at high risk of becoming infected with HIV through sex or injection drug use. 

Specifically, the Centers for Disease Control and Prevention (CDC) recommends that PrEP be considered for people who are HIV negative and in an ongoing sexual relationship with an HIV-positive partner. This recommendation also includes anyone who isn’t 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 using a condom or been diagnosed with a sexually transmitted disease (STD) in the past 6 months, or
  • is a 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 (for example, people who inject drugs or women who have bisexual male partners).

PrEP is also recommended for people who have injected drugs in the past 6 months and have shared needles or works or been in a drug treatment program in the past 6 months.

If you think PrEP may be right for you, talk to your health care provider.

How well does PrEP work?

PrEP is most effective when taken consistently each day. According to CDC, by using PrEP every day, you can lower your risk of getting HIV from sex by more than 90% and from injection drug use by more than 70%. Adding other strategies, such as condom use, along with PrEP can reduce a person’s risk even further.

Does PrEP cause side effects?

Some people taking PrEP may have side effects, like nausea, but these side effects are usually not serious and go away over time. Talk to your health care provider if you have any side effect that bothers you or that does not go away.

What should I do if I think PrEP could help me?

If you think you may be at high risk for HIV and that you might benefit from PrEP, talk to your health care provider. If you and your health care provider agree that PrEP may be a good choice for you, the next step is an HIV test to be sure you don’t already have HIV. If you are HIV negative and additional tests show that PrEP is likely safe for you, your health care provider can give you a prescription for PrEP. 

Many health insurance plans cover the cost of PrEP. A commercial medication assistance program is available for people who may need assistance paying for PrEP.

What happens once I start PrEP?

Once you start PrEP, you will need to take PrEP every day. Studies have shown that PrEP is much less effective if it is not taken every day.

You should keep using condoms while taking PrEP. While taking PrEP daily can reduce your risk of HIV infection, the continued use of condoms can help reduce your risk even further. PrEP also does not reduce the risk of getting any other STDs. Read this fact sheet from CDC for information on how to use condoms correctly.   

You must also take an HIV test every 3 months while taking PrEP, so you’ll have regular follow-up visits with your health care provider. If you are having trouble taking PrEP every day or if you want to stop taking PrEP, talk to your health care provider.

How can I learn more about PrEP?

Visit the websites below from CDC to learn more about PrEP. This fact sheet is based on information from these sources: 

Need Help?

  • Call 1-800-448-0440
  • (1 p.m. to 4 p.m. ET)
  • Send us an email