Seismic Shift in the Deodorant Business: A Scent Deeper Than Love — Why Body Odor Emitted During Women's Ovulation Calms Male Stress

1. Background—"Are Humans Attracted by Smell?"

In the animal kingdom, pheromones influence romance and territory. However, the question of "Do humans have pheromones?" has been a long-standing debate. In July 2025, Professor Kazuhiro Kahara and his team from the University of Tokyo published a new paper in iScience, providing evidence that takes a step further in answering this question.University of Tokyo.

2. Essence of the Research

Researchers collected axillary odors from over 20 female participants at four stages of their menstrual cycle and conducted a comprehensive analysis of volatile components using GC-MS. They extracted three molecules that significantly increased during the ovulation phase (6-methyl-5-hepten-2-one = 6MHO, geranyl acetone = GA, and squalene oxide), and created a model odor by adding these to a "standard axillary odor."Neuroscience News.

3. Behavioral and Physiological Tests

Male participants (aged 20–30, heterosexual) conducted ① odor evaluation, ② impression evaluation of simultaneously presented female facial photographs, and ③ salivary amylase measurement. Results showed that the ovulation phase odor was, on average,

• 28% less unpleasant

• 16% more attractive

• 19% lower sAA concentration
  , with statistically significant differences (p < 0.01)News-Medical.

4. Between "Pheromone-like" and "Pheromone"

Researchers refrained from defining it as "human pheromone" due to reasons such as "species specificity unknown" and "receptor pathways unexplored," instead describing it as "pheromone-like compounds."Neuroscience News. This challenges the post-1990s view that "humans do not have pheromones," prompting a reconsideration of the social role of smell.

5. Voices on Social Media—Excitement and Skepticism

Reddit (r/science)

The post garnered over 10,000 upvotes, sparking heated discussions like "Verification beyond heterosexuality" and "The scent business will change."Reddit.

Blog "Odor"

welcomed the research results as a "return to physical diversity," stating that "odor aversion is a capitalist illusion."Kiyubaru Underground Museum.

General Media

The NY Post sensationally reported, "Women's axillary odor relaxes men under certain conditions," with the comment section flooded with criticisms like "aiming for clicks over science."New York Post.

6. Industrial and Cultural Impact

• Deodorant Market—A shift from the single-minded "zero odor equals justice" to products that utilize "individual subtle scents" is anticipated.

• Matching Apps—There is a possibility of incorporating scent profiles in the future to present "chemical compatibility."

• Arts and Entertainment—Recalling John Waters' 90s "Scratch & Sniff" films, olfactory presentations may be reevaluated.

7. Research Limitations and Next Steps

1. Participant Bias: Predominantly Japanese, with limited genetic diversity.

2. Same-Sex/Non-Heterosexual Reactions: Not examined in this study.

3. Neuroimaging: Mapping brain activity during odor exposure is a future challenge.
   The team is planning large-scale international collaborative trials and fMRI analysesNeuroscience News.

8. Dialogue with Existing Research

In 2024, Zetzsche et al. reported that "men do not prefer ovulation odor," sparking controversy. The current findings differ in that they found effects not from "ovulation odor itself" but from the addition of specific molecules that increase during the ovulation phase. This suggests that "cooperation of multiple molecules" may be key, and the two studies do not necessarily contradict each otherRoyal Society Publishing.

9. Conclusion—How to Read the "Invisible Chemical Language"

This study demonstrated that human olfactory communication is surprisingly sophisticated and can influence emotions and stress responses. It opens new doors not only for romance and business but also for stress care, cosmetic design, and inclusive communication through scent. In the future, we may wield "smell" as the "sixth SNS."