Study Reveals How Female Body Odor Influences Male Behavior and Perception

Researchers at the University of Tokyo set out to investigate whether female body odor, particularly during ovulation, can influence men’s behaviors and perceptions. While pheromones—the notion that chemical signals alter human behavior—remain a popular topic in culture and fiction, they have not been conclusively demonstrated in humans. This research sought to detect measurable changes in men’s responses to specific compounds in female odor.

In their study, the scientists identified three components in female armpit odor that increase during ovulation. Professor Kazushige Touhara explained, “When men sniffed a mix of those compounds and a model armpit odor, they reported those samples as less unpleasant, and accompanying images of women as more attractive and more feminine.” Alongside these impressions, a physiological effect was also observed: “Those compounds were found to relax the male subjects, compared to a control, and even suppressed the increase in the amount of amylase (a stress biomarker) in their saliva.” These findings point to body odor playing a subtle, communicative role between people. 

To reach these results, the research team used gas chromatography-mass spectrometry to analyze how the volatile chemical composition of armpit odor varied across menstrual cycle phases. “The most difficult part of the study was to determine the axillary (armpit) odor profile within a woman's menstrual cycle. Of particular difficulty was scheduling more than 20 women to ensure that axillary odors were collected at key times during their menstrual cycles,” noted Nozomi Ohgi, first author of the paper published in iScience. Each participant had to be interviewed frequently to track their cycle, and collection took over a month per person. To minimize bias, the study was conducted “blind,” meaning neither subjects nor experimenters could identify which odors were being sampled or why during testing.

Despite the suggestive results, Professor Touhara cautioned against labeling these compounds as true human pheromones. “We cannot conclusively say at this time that the compounds we found which increase during the ovulation period are human pheromones...We were primarily focused on their behavioral or physiological impacts, in this case, the reduction of stress and change in impression when seeing faces. So, at this moment, we can say they may be pheromonelike compounds.”

Looking ahead, the team intends to broaden the participant pool, undertake deeper chemical analysis, and study how these odorants may influence brain activity related to emotion and perception.