What to Do If You Are Accidentally Exposed to HIV

Averting Infection With Post-Exposure Prophylaxis (PEP)

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If you think that you've been accidentally exposed to HIV, either through sex or other high-risk modes of transmission, there are medications you can take—called post-exposure prophylaxis (PEP)—that can significantly reduce your risk of infection if started in a timely manner.

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Examples of high-risk exposure include:

What Is PEP?

PEP consists of a 28-day course of antiretroviral drugs that must be taken completely and without interruption. In order to minimize the risk of infection, PEP must be started as soon as possible—ideally within 1 to 36 hours of exposure.

While PEP can be administered within 72 hours of exposure, the chances of averting an infection are best the sooner you start. The more time that passes, the more that the virus is able to migrate from the site of the exposure to nearby cells and tissues.

PEP is also prescribed to healthcare workers who have had occupational exposure to HIV, such as through contact with infected blood or a needle-stick injury.

Takeaway #1

If you think you have been exposed the HIV, do not wait. Go immediately to your nearest emergency room or walk-in clinic. Do not wait until the morning to call your doctor.

HIV Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Doctor Discussion Guide Woman

Before Treatment

Once you arrive at the hospital or clinic, you will be asked about the exposure incident by a doctor, nurse, and dedicated staff member. Do not be embarrassed to describe what happened. The aim of the interview is to ascertain if the incident poses a viable risk of transmission. This can help you avoid taking drugs you don't actually need.

On the other hand, PEP may not be viable if you have waited too long to seek treatment.

If it is determined that you are at substantial risk of infection, you will be given a rapid HIV test to determine whether you are HIV-positive or HIV-negative.

  • If you are HIV-positive, it means that you have HIV. A second test will then be given to confirm the results, after which a trained healthcare worker will discuss your results and explain how HIV is diagnosed and treated.
  • If you are HIV-negative, it means there is no evidence of the virus in your blood. The healthcare worker will explain what a negative result does and does not mean and walk you through the steps of PEP.

If PEP is authorized, you will be advised about how to take the drugs, what side effects may occur, and the importance of treatment adherence.

Additional tests may be ordered to screen for sexually transmitted diseases or hepatitis B if needed. Emergency contraception may also be prescribed in cases of rape or sexual assault.

Takeaway #2

PEP is not recommended if you delay for more than 72 hours from the time of the exposure. This does not mean you will get HIV—only that the potential benefits of PEP will have been lost.

How PEP Is Prescribed

In the past, PEP consisted of either one, two, or three antiretroviral drugs based on the severity of the exposure. Part of the reason for this was that earlier generation drugs were more toxic and often caused intolerable side effects. Newer generation antiretrovirals used for PEP are far more tolerable and tend to cause few, if any, side effects.

PEP can be used for both adults and adolescents. The CDC recommends several options, two of which are preferred and the other of which is an alternate if the preferred drugs aren't available.

Option Recommended Treatment
Preferred Option 1 Truvada (tenofovir + emtricitabine) once daily plus Tivicay (dolutegravir) once daily
Preferred Option 2 Truvada (tenofovir + emtricitabine) once daily plus Isentress (raltegravir) twice daily
Alternative Option Truvada (tenofovir + emtricitabine) once daily plus Prezista (darunavir) once daily plus Norvir (ritonavir) once daily

A follow-up HIV test would then be scheduled, usually within four to six weeks of the completion of PEP. If the test is negative, you will be counseled on how to reduce your risk of HIV moving forward.

Takeaway #3

Once started, you need to complete the entire 28-day course of treatment. If you experience intolerable side effects, call your doctor or clinic immediately; other drugs may be used. Whatever you do, do not stop or miss doses.

HIV Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Doctor Discussion Guide Woman

Effectiveness of PEP

The effectiveness of PEP has typically been evaluated in healthcare settings, mainly because risk assessment, treatment, and post-treatment protocols are standardized and the results are more easily tracked.

In non-occupational settings, this is not the case. Not only do the routes of exposure vary, but it is often difficult to assess whether treatment was adhered to, whether the details of the incident were accurate, or whether PEP was even necessary.

With respect to PEP in healthcare settings, an early study published in the New England Journal of Medicine concluded that PEP administered after a percutaneous (needle puncture) wound reduced the risk of HIV by 81%. Subsequent studies suggest the results may today be closer to 90% or greater.

Takeaway #4

Based on the current body of evidence, it can be presumed that PEP can significantly reduce the risk of getting HIV through sex or injecting drug use if started early and taken to completion.

A Word From Verywell

PEP is not a morning-after pill. If you are at high risk of getting HIV, speak with your doctor about a preventive strategy known as pre-exposure prophylaxis (PrEP) in which the daily use of Truvada can reduce your risk of getting HIV by up to 99%.

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  1. Centers for Disease Control and Prevention. Updated guidelines for antiretroviral postexposure prophylaxis after sexual, injecting drug use, or other nonoccupational exposure to HIV—United States, 2016. 2016.

  2. Cardo D, Culver D, Ciesielski C, et al. A case-control study of HIV seroconversion in health care workers after percutaneous exposure. New Eng J Med. 1997;337:1485-1490. doi:10.1056/NEJM199711203372101

  3. Beymer MR, Weiss RE, Bolan RK. Differentiating nonoccupational postexposure prophylaxis seroconverters and non-seroconverters in a community-based clinic in Los Angeles, California. Open Forum Infect Dis. 2017 Spring;4(2):ofx061. doi:10.1093/ofid/ofx061

  4. McCormack S, Dunn DT, Desai M, et al. Pre-exposure prophylaxis to prevent the acquisition of HIV-1 infection (PROUD): effectiveness results from the pilot phase of a pragmatic open-label randomised trial.Lancet. 2016;387(10013):53-60. doi:10.1016/S0140-6736(15)00056-2