Birth-control pills are known to affect women’s taste in men, at least in laboratory experiments. Now a study of real-world couples suggests that this pill-related preference change could have long-term consequences for a relationship’s quality and outcome.

In the lab, women using oral contraceptives show a weaker preference for masculine men—those with high testosterone levels and the corresponding physical hallmarks—than their non-pill-using counterparts. To investigate this issue in a real-world setting, psychologist S. Craig Roberts of the University of Stirling in Scotland and his collaborators gave online surveys to more than 2,500 women from various countries. According to the results, published online October 12 in the Proceedings of the Royal Society B: Biological Sciences, participants who used hormonal contraceptives while choosing their partner were less attracted to him and less sexually satisfied during their relationship than were individuals who did not use hormonal birth control. Pill users were happier with their mate’s financial support and other nonsexual aspects of the relationship, however, and they were less likely to separate.

This relationship stability might be caused by the bias of women on the pill toward low-testosterone men, who tend to be more faithful. Roberts suggests that women who met their mate while taking the pill might want to switch to nonhormonal contraceptives several months before getting married to test whether their feelings for their partner remain the same.

This article was published in print as "The Problem with the Pill."