Switch On Your HIV Smarts.

New Study on PrEP and Sexual Risk Behavior

, by San Francisco AIDS Foundation

BluePillsCROPDo people start having “riskier sex” when they begin taking PrEP to avoid HIV infection? Apparently not, according to a report in the December 18 edition of PLoS ONE.

Although daily Truvada PrEP has been shown to significantly reduce HIV acquisition risk in clinical trials, concern has remained that people who already use condoms for HIV prevention will stop using this effective tool when they start using PrEP; should they then use PrEP inconsistently, they could be at higher risk for HIV. The large iPrEx trial of daily PrEP found no such “risk compensation” reported by study volunteers, but a recent follow-up study looked beyond these self-reported data.

“After the initial iPrEx study, there was concern that self-reported behavior may not tell the whole story,” said iPrEx principal investigator Robert Grant in a press release from the University of California at San Francisco. In follow-up research, Grant and colleagues assessed PrEP users’ sexual behavior with unique approach: “Here, we not only gathered behavioral data, but we also tested each participant for both HIV and syphilis—allowing us to map over time how reported changes in overall behavior correlated with actual changes in infection rates.”

The result? “If risk compensation were occurring, those who believed they were receiving Truvada and that it was effective would be more likely to increase their sexual risk behavior,” explained Julia Marcus, first author of the PLoS ONE article, in the same press release. “However, our results revealed the opposite: rates of both HIV and syphilis infections went down, and there was no increase in sexual risk behavior.”

To learn more about the study, and what it means for real-world use of PrEP, see Liz Highleyman’s summary of the article, excerpted below and available in full at HIVandHepatitis.com. And for answers to your questions about PrEP and where it fits in the HIV prevention toolkit, visit PrEPfacts.org.

PrEP Does Not Promote Increased Sexual Risk Behavior among Gay Men

By Liz Highleyman

December 23, 2013

Using Truvada (tenofovir/emtricitabine) for pre-exposure prophylaxis (PrEP) to prevent HIV infection was not associated with an increase in sex without condoms and it appears to promote active engagement in risk reduction, according to a report in the December 18, 2013, edition of PLoS ONE.

…Julia Marcus and Robert Grant from the Gladstone Institute of Virology and Immunology and colleagues aimed to determine whether people who used PrEP in the study appeared to be having more risky sex. Self-reported sexual risk behavior decreased overall in iPrEx, but this may be affected by reporting bias, they noted as background. This analysis, therefore, looked at biomarkers of sexual risk behavior.

Sexual practices were assessed at study entry and then quarterly thereafter. At 12 weeks, participants were asked whether they thought they had been randomly assigned to Truvada or placebo and how effective they thought PrEP would be. Among participants with at least 1 follow-up assessment, sexual behavior, prevalence of syphilis, and HIV infection were compared according to perceived treatment assignment, actual treatment assignment, and perceived PrEP efficacy.


  • Overall, both acute HIV infection and syphilis incidence decreased during follow-up.
  • Participants who thought they were receiving Truvada reported receptive anal intercourse with more partners prior to starting PrEP compared with those who thought they were receiving placebo (12.8 vs 7.7, respectively).
  • Believing one had been assigned to take Truvada was not associated with an increase in receptive anal intercourse without a condom.
  • People who thought they were assigned to Truvada also did not report a decrease in sex without condoms after stopping their study drug.
  • In the placebo arm, there were trends toward lower HIV incidence among participants who believed they were receiving Truvada (incidence rate ratio [IRR] 0.8; p=0.26) and who thought Truvada was highly effective (IRR 0.5; p=0.12).
  • Younger men, transgender women, and participants who reported depression were more likely to have anal sex without condoms.

“There was no evidence of sexual risk compensation in iPrEx,” the study authors concluded….

Click here to read the full summary at HIVandHepatitis.com.


4 Responses to New Study on PrEP and Sexual Risk Behavior

  1. Steve says:

    Are Condoms really an effective tool?

    It has recently been reported that;

    1. Condoms only stop seven out of ten anal transmissions.

    2. Long-term 100% condom use is a minority behaviour: only one-in-six gay men actually managed to maintain it over the three- to four-year time frame of the analysis.

    Citation: Dawn Smith of the US Centers for Disease Control (CDC) reported at the 20th Conference on Retroviruses and Opportunistic Infections (CROI 2013)

  2. sam logan says:

    i am a hetero AIDS positive, with other conditions, not related but complicated my conditions. I am not against anyone’s preferences. I am really concerned with all this behavior that is being done by certain subcultures within the gay and straight communities of HIV positives. Among the gay men, I keep on hearing “we want to be accepted by society” and “men cant help themselves, they cant control their urges.” yet as a hetero, i know many men and women who have no choice but to control our “urges” no excuse for not doing so, gay, by, strait, trans, noone is exempt from responsible and controlled behavior. we are not kids. if you want to do high risk fun, then quit wining and take the bad with it. Dont ask the rest of us to accept the negative attitudes we get from others, for what you do. i am a female, i was promiscuous, i liked risky behavior, and face it we all hate rubbers, but i have a choice, use them or do without. I do without because i am tired of all the hetero men who still go on sleeping with many women, and married. preying on every gay/strait dating site, i have seen all the same creeps on every site out there. I am living without many things i enjoyed, i am not asking to be accepted, i dont care what society accepts or approves of. i miss my freedoms and choices and doing what i liked. so, i dont blame my lack of control, or urges. copouts are rampant in society, people grow up, accept it, or do without. you did it to yourselves so if you want pity or compassion, then stop making it such a big deal to announce it to the entire world. only you are the ones making it an issue. i dont want my business on every public network and site. i value myself more than that. besides being a government target, and lab rat is enough from me.

    • San Francisco AIDS Foundation says:

      Thanks for sharing your perspective, Sam. Sex, intimacy, and pleasure are valuable and meaningful parts of life for countless people–gay, straight, bi, trans, and beyond–and wanting those things doesn’t make us irresponsible or out of control. Likewise, wanting to be open about having HIV without experiencing stigma and discrimination is not whining; it’s simply expecting the same respect and rights as HIV-negative people. That’s why BETA presents new information from HIV science, policy, and advocacy: So folks can make informed decisions around their health and advocate for their own well-being.

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