Other research has uncovered a relationship between the sense of smell and pill use. Research by Steve Gangestad, a University of New Mexico psychology professor, showed that women taking oral contraceptives had no significant preference for the smell of males with symmetrical features vs. asymmetrical features. Symmetry in features is a measure of attractiveness and genetic fitness. Women not taking the pill preferred the smell of males with symmetrical features during their most fertile time. "What we found is that the pill may actually upset normal preferences for choosing mates," says Gangestad. https://abcnews.go.com/Health/story?id=117158&page=1 Recent research suggests that the contraceptive pill—which prevents women from ovulating by fooling their body into believing it is pregnant—could affect which types of men women desire. Going on or off the pill during a relationship, therefore, may tempt a woman away from her man. https://www.scientificamerican.com/article/birth-control-pills-affect-womens-taste/