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When pheromones are mentioned, the collective imagination immediately takes flight: an invisible chemistry that, as in insects or certain mammals, supposedly governs our attraction and guides our behavior. Yet, as soon as science examines these signals in humans, these certainties crumble. Experimental studies, both old and new, converge on the same conclusion: if chemical communication exists in us, it bears no resemblance to the classic animal model. And above all, it remains to be proven!
"Aphrodisiac" perfumes?
A study published in 2017 in the journal Royal Society Open Science focused on two molecules Long promoted by the "aphrodisiac" perfume industry: androstadienone and estratetraenol. Marketed since the 1990s as "human pheromones", these substances had never been scientifically validated.
To test them, Australian researchers exposed 94 heterosexual volunteers (43 men and 51 women) to these compounds, then to a control scent the following day. The participants were then asked to determine the sex of neutral faces or to rate the attractiveness and risk of infidelity of people of the opposite sex. If these molecules acted like true pheromones, they should have influenced these judgments. However, no statistically significant difference was observed. "The results are consistent with those of other experimental studies which suggest that these two molecules are unlikely to be human pheromones." having an impact on human beings, the authors of the study concluded.
Some studies describe slight changes in mood or attention with androstadienone, but studies They criticize their protocol for being not very rigorous, their sample size and their situation being far removed from real-world conditions.
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A pheromone involves an innate, universal and reproducible mechanism
This scientific caution has not been refuted in recent years. In 2023, a research team led by the Czech Jan Havlíček published a comprehensive synthesis in the journal Perspectives on Psychological Science, providing an overview of human chemical communication. She explains that our sense of smell is much more refined than previously thought: we emit dozens of volatile compounds and our brain discriminates them at minute concentrations.
But the study's authors point out that the very definition of a pheromone implies an innate, universal, and reproducible mechanism: a criterion that no candidate human molecule has yet met. The few effects reported in some studies, often modest, vary considerably depending on the experimental context, the culture, or the sex of the person exposed. In other words, nothing that resembles the stereotypical reaction of an insect or rodent.
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Thus, according to biologist Tristram Wyatt of Oxford University (Great Britain), all the so-called "human pheromones" sold commercially are based on no solid foundation. In a study published in 2015 in the journal Proceedings of the Royal Society B, He explained that the best evidence of pheromones might come from… newborns. In them, olfactory behaviors (direction towards the scent of the mother's breast, soothing by certain olfactory signatures) seem more "raw," less influenced by learning or social norms. Could this be a line of research that one day lead to the identification of genuine human chemical signals?
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