In the animal kingdom, female body scent acts like a quiet broadcast, especially during ovulation, telling males it’s prime time for reproduction. These natural signals can spark changes in male behavior or body responses.
Humans share a version of this, too. Research suggests men tend to find women’s scent more appealing during their fertile window. But what’s happening under the surface biologically? That part’s still a mystery that scientists are trying to unravel.
Researchers in Tokyo looked at how women’s body odor affects men. They found that certain scent compounds increase during ovulation and can gently influence men’s feelings.
When these scents were added to sweat samples, men thought the smell was nicer and rated matching faces as more attractive. The scents also appeared to lower stress levels. While it’s not proof of human pheromones, the study suggests scent might quietly shape how people relate to each other.
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Pheromones often show up in rom-coms as magical scent signals that spark attraction, but in reality, science hasn’t proven they exist in humans. Still, a recent study from the University of Tokyo found that certain body odor compounds, especially during ovulation, might subtly influence men’s emotions and perceptions. It’s not quite proof of pheromones, but it does hint at scent playing a quiet role in how we connect.
Scientists discovered three scent compounds that rise in women’s body odor during ovulation. When men caught a whiff of these added to simulated armpit sweat, they found the scent more pleasant, and saw women’s photos as more attractive and feminine.
Even more interesting? The scents seemed to chill the guys out, easing stress and keeping a stress chemical in their saliva from spiking. It’s not a love potion, but it hints that our noses might be quietly guiding social signals between men and women.
Previous studies have shown that women’s scent changes during their menstrual cycle, particularly during ovulation, when men tend to find it more pleasant. But no one had cracked the code on what exactly those scent changes are. That’s where the Tokyo research team stepped in.
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Using a super-sensitive sniffing technique called gas chromatography-mass spectrometry (it’s like CSI for smells), they pinpointed specific compounds that shift across the menstrual phases. But getting those samples wasn’t exactly a walk in the lab; each of the 20+ women had to be tracked over a month, with frequent check-ins on things like body temperature to catch the right moment for collecting armpit odor (yes, armpit!).
The team also ran the scent tests blind, so participants had no clue what they were smelling, or if they were even smelling anything at all. That helped eliminate guesswork or bias from the results.
While this doesn’t prove humans have pheromones like other animals do, it opens up a fascinating window into how scent might be whispering subtle cues in our social interactions.
Professor Kazushige Touhara said, “We cannot conclusively say at this time that the compounds we found, which increase during the ovulation period, are human pheromones. The classical definition of pheromones is species-specific chemical substances that induce certain behavioral or physiological responses.”
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“But from this study, we can’t conclude whether the axillary odors are species-specific. 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.”
The researchers aren’t stopping at just sweat and smiles. They plan to widen their participant pool to rule out whether specific genetic quirks are skewing results. On top of that, they’re diving deeper into the chemical soup of scent compounds and scanning brain activity to see how ovulation, linked odors, might light up emotional and perceptual zones upstairs. In short, this scent science is heading from the armpit to the mind.
Journal Reference
- Nozomi Ohgi, Mika Shirasu, Yusuke Ogura, Yukei Hirasawa, Masako Okamoto, Rieko Kawamura, Hirosato Takikawa, Kazushige Touhara, “Human ovulatory phase-increasing odors cause positive emotions and stress-suppressive effects in males,” iScience: July 28, 2025, DOI: 10.1016/j.isci.2025.113087
