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Pre-Exposure Prophylaxis (PrEP)

Photo of HIV medication

Pre-exposure prophylaxis (or PrEP) is a way for people who do not have HIV but who are at very high risk of getting HIV to prevent HIV infection by taking a pill every day. The pill (brand name Truvada) contains two medicines (tenofovir and emtricitabine) that are used in combination with other medicines to treat HIV. When someone is exposed to HIV through sex or injection drug use, these medicines can work to keep the virus from establishing a permanent infection.

When taken daily, PrEP is highly effective for preventing HIV. 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. PrEP is much less effective if it is not taken consistently.

As PrEP only protects against HIV, condoms are important for the protection against other STDs.

Condoms are also an important prevention strategy if PrEP is not taken consistently.

Resources for Providers

PrEP and PEP Toolkit for Providers

Prescribe HIV Prevention
An initiative encouraging health care providers to learn about using PrEP and PEP to reduce new HIV infections.


En Español


PrEP Consultation Service for Clinicians

1-855-448-7737 (1-855 HIV-PREP)
11 a.m. – 8 p.m. ET , Monday-Friday
For more information on the services offered through the PrEPline, visit the National Clinicians Consultation Center.

Free Continuing Education for Healthcare Providers

Advancing PrEP in Practice: Practical Strategies for Everyday Challenges
This activity is intended for primary care physicians, ID/HIV specialists, and public health and preventive medicine specialists.The goal of this activity is to improve recognition among primary care providers of patients who could benefit from human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP) medications.
Faculty: Colleen F. Kelley, MD, MPH

Preventing HIV Infection in the Primary Care Setting: The Role of Pre-Exposure Prophylaxis (PrEP)
This CME activity can be completed through Medscape, and is intended for primary care physicians, ID/HIV specialists, nurses, and public health & preventive medicine specialists. The goal of this activity is to discuss the use of PrEP in the primary care setting, including patient assessment and management, CDC guidelines, and tips for incorporating this into practice. Requires free Medscape log in.
Moderator: Michael S. Saag, MD
Faculty: Demetre C. Daskalakis, MD, MPH; Christian B. Ramers, MD, MPH, AAHIVS; Dawn K. Smith, MD, MS, MPH

PrEP Guidelines


FDA has approved daily oral antiretroviral preexposure prophylaxis (PrEP) with Truvada for adolescents and adults who weigh at least 35 kilograms (77 pounds).

On May 15, 2018, the Food and Drug Administration approved an indication for Truvada for preexposure prophylaxis (PrEP) in adults and adolescents who weigh at least 35 kg (77 lb). The indications for PrEP, initial and follow-up prescribing and laboratory testing recommendations are the same for adolescents and adults.

This change for adolescent use will be incorporated into the next update to the PrEP guidelines.

CDC has released a 2017 update to the clinical practice guidelines for PrEP. The new guidelines

  • Provide clear criteria for determining a person’s HIV risk and indications for PrEP use.
  • Require that patients receive HIV testing to confirm negative status before starting PrEP.
  • Recommend regular monitoring of HIV infection status, side effects, adherence, and sexual or injection risk behaviors.
  • Underscore importance of counseling about adherence and HIV risk reduction, including encouraging condom use for additional protection.
  • The update to the providers’ supplement offers clinicians additional materials and tools for use when prescribing PrEP.

The guidelines recommend that PrEP be offered to people who are HIV-negative and at substantial risk for HIV.

For sexual transmission, this includes anyone who 1) is not in a mutually monogamous* relationship with a partner who recently tested HIV-negative, and 2) is a

  • gay or bisexual man who has had anal sex without a condom or been diagnosed with an STD in the past 6 months; or
  • 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 have bisexual male partners).

For people in HIV-discordant couples where one sexual partner is HIV-positive and the other is HIV-negative. PrEP can be especially useful when the HIV-positive partner is not taking antiretroviral medications or does not have an undectectable viral load. Health care providers should also discuss the use of PrEP with HIV discordant heterosexual couples during conception and pregnancy as one of several options to protect the partner who is HIV-negative.

For people who inject drugs, this includes those who have injected illicit drugs in the past 6 months and who have shared injection equipment or been in drug treatment for injection drug use in the past 6 months.

Patients on PrEP should return to their health care provider every 3 months for a repeat HIV test and other follow-up. At this time, the provider can write a prescription refill, offer counseling about medication adherence and risk reduction, test for STDs if necessary, and assess side effects.

PrEP is only for people who are at ongoing substantial risk of HIV infection. For people who need to prevent HIV after a single high-risk event of potential HIV exposure—such as unprotected sex, needle-sharing injection drug use, or sexual assault—there is another option called postexposure prophylaxis, or PEP.  PEP must begin within 72 hours of exposure. See our PEP guidelines.

* Mutually monogamous means that you and your partner only have sex with each other and do not have sex outside the relationship.

Additional PrEP Resources

PrEP Locator