Quantification of “Mercy Sex” in Heterosexual Women

Women with hypoactive sexual desire disorder (HSDD) lack the thoughts, desire, or receptivity to sexual desire, causing personal difficulty and distress (DSM IV-TR). However, HSDD clinical trials evaluating testosterone therapy, flibanserin, and bremelanotide spanning nearly a decade show women with HSDD, encompassing low to no sexual desire, are still engaging in sexual activity. We aimed to define this sexual activity as "mercy sex", quantify its frequency, and provide hypothetical explanations for this behavior. We reviewed baseline data on sexually satisfying events (SSEs) from a representative convenience sample of published, peer-reviewed, prospective, randomized, placebo-controlled trials of women with HSDD. Baseline data were assessed across time, age, reproductive status, and geography. Women in these studies engaged in "mercy sex" about 2.5 times/month despite their documented HSDD. These results have important implications for further HSDD clinical research, as mercy sex frequency may skew therapeutic efficacy while having significant implications in calculating trial sample size, and assessing a clinically meaningful response to therapy, when SSEs are used as a primary endpoint. Although this paper explores only a biopsychosocial explanation for the phenomenon of mercy sex in clinical trials of HSDD therapies, it provides a valuable understanding that will benefit patients, clinicians, and researchers.