Will the HIV Prevention Pill Encourage High Risk Sex?

Taking a Balanced Look at the Often-Contentious Debate

Tina Franklin

HIV pre-exposure prophylaxis, popularly known as PrEP, consists of a daily antiretroviral pill which has been shown to reduce the risk of acquiring HIV by as much as 92%. That risk can be reduced even further, to as high as 98%, if the HIV-positive partner is on antiretroviral therapy and is able to sustain a so-called "undetectable" viral load.

While PrEP usage is on the rise in certain populations, including gay men and heterosexuals at higher risk of infection, lingering doubts continue to keep many who might otherwise benefit from PrEP from accessing treatment.

Certainly the vigorous, and often acrimonious, debate sparked by the AIDS Healthcare Foundation (AHF) in 2014—in which the organization asserted, in nationwide ads, that "the scientific data do not support the large-scale use of (PrEP)"—only helped add to the public confusion.

In addressing the controversy, AHF president Michael Weinstein stated in an interview with the Associated Press that "If something comes along that's better than condoms, I'm all for it, but (PrEP) is not that. Let's be honest: it's a party drug."

So who is right? Are people being led astray as Weinstein has suggested? Will gay men and others abandon condoms and other safer sex practices if they believe themselves to be shielded from HIV?  

And more importantly, will PrEP end up increasing HIV transmissions at a time when the U.S. and other countries are struggling to rein in their infection rates?

Weighing the Evidence

While researchers and health officials readily acknowledge that PrEP could reduce perceptions of HIV risk among those who desire condom-less sex (known as behavioral disinhibition) or who consider condom-less sex an acceptable risk when taking PrEP (known as sexual risk compensation), most studies seem to suggest that PrEP does not inherently alter sexual behaviors.

Seven high-quality, randomized trials conducted between 2010 and 2014—ranging in size from 1,219 heterosexual men and women in Botwana to 2,499 men who have sex with men (MSM) in the U.S. to 4,474 HIV serodiscordant couples in Kenya and Uganda—each examined sexual risk compensation among PrEP users and concluded that PrEP was not associated with increased sexual risk behaviors and that, in all but one study, there were no increases in sexually transmitted diseases either.

That is not to say that we'll necessarily see the same results in real-world settings, particularly since each of the trials provided and emphasized condom use during the course of the investigation. Since this is generally not done in clinical practice, it does question whether sexual risk-taking might increase as traditionally happens following the release of a biomedical HIV breakthrough.

But does this mean that PrEP will lower guards to such a degree as to place individuals—and entire populations—at increased risk of HIV? Most research seems to suggest that it won't.

According to Jill Blumenthal, MD of the Weill Cornell Medical College of Cornell University and Richard Haubrich, MD of the AIDS Clinical Trials Group (ACTG), behavioral disinhibition can only increase HIV transmissions if the prevention strategy has low efficacy. Given the high clinical effectiveness of PrEP, they say, even if riskier sex behaviors do occur, the added protection of PrEP would still likely lower infection rates.

This is supported by behavioral research from Hunter College in New York, which took a flip-side approach by evaluating the acceptability of PrEP among gay men who had already reported non-condom use and other high-risk sexual behaviors.

In their conclusions, the authors suggested that the high willingness of this group to use PrEP didn't so much reflect sexual risk compensation as signal an increased response to HIV by those who fully understood themselves to be at high risk.

Ultimately, it's not so much a question as to whether PrEP will encourage high-risk behaviors but rather if PrEP, as a strategy, can decrease HIV risk even in those at highest risk?

Based on the current evidence, the answer remains a resounding "yes."


Blumenthal, J. and Haubrich, R. "Risk Compensation in PrEP: An Old Debate Emerges Again." Virtual Mentor. November 1, 2014; 6(11):909-915.

Liu, A.; Vittinghoff, E.; Chillag, K.; et al. "Sexual risk behavior among HIV-uninfected men who have sex with men (MSM) participating in a tenofovir pre-exposure prophylaxis (PrEP) randomized trial in the United States." Journal of Acquired Immune Deficiency Syndrome. Online edition; March 11, 2013; DOI:10.1097.

Guest, G.; Shattuck, D.; Johnson, L.; et al. "Changes in sexual risk behaviour among participants in a PrEP HIV Prevention Trial." Sexually Transmitted Diseases. December 2008, 35(12):1002-1008. .

Marcus, J.; Glidden, D.; Mayer, K.; et al. "No evidence of sexual risk compensation in the iPrEx trial of daily oral HIV preexposure prophylaxis." PLoS|One. December 18, 2013;8(12):e81997.

Golub, S.; Kowalczyk, W.; Weinberger, C.; et al. "Pre-exposure prophylaxis and predicted condom use among high-risk men who have sex with men." Journal of Acquired Immune Deficiency Syndrom. August 2010; 54(5):548-555.

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