Human ovulatory phase-increasing odors cause positive emotions and stress-suppressive effects in males

In many animals, olfactory cues are key for recognizing their sex, kinship, and reproductive status. In humans, it has been proposed that males find female body odors attractive during the ovulatory phase, coinciding with peak fertility. However, the molecular and physiological foundations of this attractiveness remain unclear. In this study, we combined sensory evaluation with gas chromatography-mass spectrometry for chemical analysis and identified volatile compounds that fluctuate across menstrual cycle phases. We identified three ovulatory phase-increasing compounds that mitigate the basal unpleasant axillary odor, resulting in the ovulatory-phase body odor being perceived as the most pleasant by males. Additionally, these compounds alleviated hostility and stress induced by the basal axillary odor, leading to relaxation in males and an enhanced positive impression of female facial images. Our results suggest that several ovulatory phase-increasing compounds may contribute to the positive effects of ovulatory female odor on males, as proposed in previous research.