Researchers quantify the rate of “mercy sex” among women with low sexual desire

Women experiencing chronic low sexual desire still regularly engage in sexual activity with partners, according to a study quantifying this behavior known as "mercy sex." This occurs about two and a half times per month and may influence how treatments for low sexual desire are evaluated. Hypoactive sexual desire disorder is a condition where individuals lack sexual thoughts or desire, causing personal distress.

Clinical trials typically measure treatment success by the frequency of sexually satisfying events, which include any sexual activity considered fulfilling by the participant. In 2015, the FDA approved the first drug for premenopausal women with this condition, requiring companies to measure success by tracking sexually satisfying events.

Researchers Nikita Guptan and James A. Simon at IntimMedicine Specialists in Washington, D.C., noticed a discrepancy in clinical trials where women diagnosed with complete lack of sexual desire were still logging multiple sexual events before treatment. They define mercy sex as consensual participation in sexual acts not for personal arousal but to fulfill perceived obligations.

The researchers analyzed data from multiple randomized, placebo-controlled trials spanning nearly a decade, testing three different medical treatments for low sexual desire. In trials involving testosterone patches, women reported an average of 2.5 to 2.9 sexually satisfying events per 28 days. Similar patterns emerged in trials examining flibanserin, an oral medication approved for low sexual desire, with women reporting 2.0 to 3.0 sexually satisfying events per month.

However, baseline frequencies were notably lower in trials evaluating bremelanotide, an injectable medication, averaging about 1.2 events per month. The researchers suggest that women with low desire consistently engage in sex due to a biopsychosocial framework. From an evolutionary perspective, women may participate in sex to maintain relationship stability and prevent partners from seeking intimacy elsewhere.

In modern contexts, this could translate to engaging in obligatory sex to preserve long-term relationships or fulfill emotional needs for closeness, even when physical desire is absent.