UC Santa Barbara

Previous literatures have shown that a woman’s body odors during the fertile window (-5 to 0 days before ovulation) were rated by men as more attractive compared to odors outside the fertile window. However, few researches have looked at the underlying hormones that could be regulating this effect, and none have looked at the relationship between women’s within-cycle shift in hormones and the within-cycle shifts in odor attractiveness. The current research examined the effects of estradiol and progesterone concentrations on women’s odor attractiveness throughout the menstrual cycle. Forty-six donor women were instructed to wear an underarm pad overnight every five days for 30 days and provided saliva samples (assayed for estradiol and progesterone) in the morning of odor collection. These women also provided daily luteinizing hormone (LH) tests. A total of 66 men then rated the pleasantness, sexiness and intensity of the odor samples in five separate sessions. And the attractiveness ratings were regressed on donors’ estradiol and progesterone concentrations. We found that odor samples during the donor women’s late fertile window (-2 to 0 days before ovulation) were rated as more attractive. Additionally, we found no effect of estradiol or progesterone on odor attractiveness within women. However, a positive effect of estradiol and a null effect of progesterone on odor attractiveness were found between women, which offer support to the position that men have evolved to attend to women’s general reproductive condition, rather than detecting women’s ability to conceive at that specific time. Since none of the hormones measured in this study can account for the late fertile window effect, further investigation is needed to explain this shift in odor attractiveness during the late fertile window.