“Our study results tell us that there are pheromones produced in the male underarms that have nothing to do with sex but can affect the physiology and mood of the recipient,” says co-author George Preti, a member of the Monell Chemical Senses Centre and an adjunct professor at the university.

Pheromones are chemical signals emitted by an animal or in this case a person that causes changes in behavior or physiology in other people. Most well known pheromones are associated with influencing sexual behavior, but researchers say the pheromone found in the male underarm does not influence sexual behavior but rather relaxes women and in some instances even alters their mood.

Preti and his colleague, Charles Wysocki recruited 18 heterosexual women between the ages of 25 and 45 for the study. The women had regular menstrual cycles, normal hormonal levels, and regular sleeping patterns and had to be within 15% of their ideal body weight at the start of the study.

Each of the women were followed for three full menstrual cycles, where researchers simply recorded the women’s hormone levels using urine samples during the first and third cycle, but within the first seven days of the second menstrual cycle, the women spent the day at the research centre.

Here, they either had a male extract or ethanol applied by a cotton pad to their upper lip area for two hours for a total of 12 hours, of which half received the ethanol for the first six hours and then the male extract for the remaining six hours, while the other half had it in the reverse order.

The male extract was collected on cotton pads placed under the arms of men who had voluntarily agreed to stop using deodorant or any soap with a fragrance for four weeks. In both cases, a similar scent was used to cover up the odour so the women didn’t know what the substance was, where the ethanol was used as a control. Remarkably, none of the women realized what they were inhaling; some even believed they were involved in a study of alcohol, perfume or even lemon floor wax.

The women were asked to evaluate their moods while they were undergoing testing of which blood samples were also drawn every ten minutes while they were at the research centre.

The researchers found that surges of Luteinising hormone (LH), an important reproductive hormone, was produced quicker after exposure to the male underarm extract, shortening the production time by 20 %.

The study also found that the women exposed to the male extract reported feeling less tense and more relaxed. “Much to our surprise, we also saw the mood changes,” Preti says.

What’s even more interesting about the qualities of the male underarm pheromone is that it also discourages close relatives from feeling attracted to each other, thus suppressing interbreeding, since the human genome, Major Histocompatibility Complex (MHC) can help women sub-consciously deduce whether a man’s MHC is different from their own.

Researchers speculate that the results of the study could boost the medical as well as cosmetic field alike, where the use of these pheromones could trigger the research for newer fertility drugs or future men’s fragrances and deodorants that could help men bag their ultimate dream girl with a simple whiff.

Share this post