One scent seems feminine, another masculine. Are those impressions determined solely by the molecules producing the odor? The question also matters when thinking about perfume imagery, but one study began with human body odor, examining two compounds.
In a study published in November 2025, Camille Ferdenzi and colleagues analyzed responses from 2,716 people at a museum in Switzerland. They focused on two sweat-odor molecules whose precursors had been reported to differ between women and men in their amounts and ratios. The results were not a simple demonstration that a clear gender impression is encoded in those molecules.
The study also examined perceptual differences according to raters’ gender and age. Here, the focus is mainly on whether the two compounds were perceived as feminine or masculine.
Not compounds found only in women or only in men
The researchers examined two compounds abbreviated as MSH and HMHA. MSH is associated with sulfurous, onion-like odors; HMHA with cheesy, rancid odors.
The study began from earlier work on how much of each compound’s precursor is secreted in the armpit. Women had been reported to have relatively more MSH precursor, while the ratio favored HMHA more strongly in men. However, individual differences were large, and the distributions for women and men overlapped considerably.
The researchers therefore directly asked whether MSH smells more feminine than HMHA. Their premise was not that one compound exists only in women and the other only in men. Differences in amounts between groups and the perception of those differences as gender impressions require separate investigation.
Smelling two museum jars in varying order
The experiment was part of an olfactory exhibition at a museum in Lausanne in 2019–2020. The analysis used responses from the period when presentation order was randomized, excluding people unable to detect the odors and other ineligible responses, leaving 2,716 participants aged 6–90.
Each compound was sprayed onto a separate cotton cloth and placed in a glass jar. Participants opened the jars, smelled them, and responded on a screen using a 0–10 scale from very masculine to very feminine. They were also asked about confidence in their judgment, pleasantness, intensity, familiarity, and whether the smell was typical of sweat.
What was measured was the impression participants formed of an odor. This was not a task of identifying someone’s gender from their actual body odor. The concentrations were also chosen to be consciously detectable and may have been higher than those in natural body odor.
A difference was found, but it was very small
Female participants tended to rate MSH as slightly more feminine than HMHA. Male participants, by contrast, showed no such difference between the two compounds.
However, the difference was very small, with substantial individual variation in responses. The effect size indicating how the difference between compound ratings varied with rater gender was approximately 0.12 in absolute value. This does not mean that 12% of people identified something correctly; it is a statistical measure for comparing the magnitude of differences.
A large sample makes small tendencies easier to detect. That is precisely why the magnitude of a difference matters, not just whether it is detected. These results did not support the view that everyone clearly distinguishes these two compounds as a female odor and a male odor.
Greater pleasantness was associated with more feminine ratings
Compound identity was not the only factor associated with gender impressions. People who found an odor more pleasant tended to rate that same odor as more feminine. The effect size for this association was approximately 0.24. Although still not large, it exceeded the value for the interaction between rater gender and compound described above.
When participants described an odor as typical of sweat, they also tended to rate it as more masculine. The gendered qualities assigned to odors were thus connected with pleasantness and the image of sweat.
However, the experiment did not manipulate pleasantness and then measure gender impressions. It does not establish that making an odor more pleasant causes it to seem more feminine, or explain why the association arises. Nor can these results alone determine how much upbringing and experience contribute.
Can these be called compounds that attract the opposite sex?
The team also considered whether these compounds might be involved in mate preferences. If they were, one might expect men to particularly prefer the compound associated with women and women to prefer the one associated with men. No such gender difference in preferences for the individual compounds was confirmed here.
This study provides no basis for calling MSH or HMHA pheromones that attract the opposite sex. Equally, it does not prove that odor plays no role at all in attraction or relationships. The study tested two individual compounds, not the complex mixtures present in actual body odor or different ratios of those mixtures.
Museum visitors also participated voluntarily. Including a broad age range is an advantage, but influences such as surrounding people cannot be standardized as closely as in a laboratory. This was not an experiment using perfume, either, so it cannot be read as a direct test of commercial perfume categories such as for women or for men.
Summary
Female raters showed a small difference in gender impressions between two sweat-odor compounds. However, perceptions varied considerably between people and were also associated with pleasantness and sweat typicality. The name of a molecule, or the gender in which it is said to be more abundant, does not seem sufficient to determine its perceived character.
When a scent seems feminine or masculine, our liking for the odor itself may also be part of that impression. Separating these aspects a little can help us understand the relationship between constituents and impressions more carefully.
References
Authors: Camille Ferdenzi, Géraldine Coppin, Christophe Bousquet, Sylvain Delplanque
Article: The perception of gender in two allegedly sex-specific body odor compounds MSH and HMHA
Journal: Scientific Reports 15, 42447 (2025)
Published: 27 November 2025
DOI: 10.1038/s41598-025-26457-4
Full text: Publisher’s article page
Original article license: CC BY 4.0
