Give pheromones to women

Male noses smell a cocktail of hormones Women smell better on fertile days

Women smell especially attractive to male noses during their fertile days. Their scent is then characterized by a hormone mix consisting of a lot of estradiol and little progesterone. The Bern researchers conclude from this that men can unconsciously read information about a woman's potential fertility from the scented cocktail. From an evolutionary point of view, that would also make sense.

The secret of the super fragrance

A special combination of sex hormones gives some women a super fragrance. Bern researchers have now found out and published it in the journal "Proceedings B" of the British Royal Society. They investigated to what extent it is a matter of taste for the individual man who he likes to smell best. And found that the men tested were very unanimous about the attractiveness of women's fragrances. Among men, certain women's smells were perceived as extremely attractive and others as less attractive.

The experiment: who smells good?

In order to rule out that appearance and sympathy influenced the men, the researchers collected the women's odor separately. 28 women placed cotton pads under their armpits during their fertile days to capture their scent. In addition, the women had to wash themselves with special, non-scented soap, were not allowed to smoke, eat spicy foods or drink alcohol.

The researchers also measured the levels of some hormones in the women's saliva, such as the estrogen estradiol, progesterone, cortisol and testosterone. In the urine, they determined the time of ovulation - i.e. the fertile days. The total of 57 participating men then sniffed the cotton pads from the most fertile night and assessed the attractiveness of each woman.

Women with a hormone combination made up of a lot of estradiol and little progesterone give off a super fragrance

The men in the lab gave the top marks to the women, who had high levels of estradiol and relatively low levels of progesterone. However - as the researchers restrict - this is a correlation study. Whether - and if so, how - the hormones lead to an attractive fragrance cannot be deduced from the study.

Apparent contradiction to earlier olfactory studies

Earlier studies had shown that women especially like to smell men when they differ from them in certain immune genes. The choice of partner is therefore influenced by the HLA genes that are important for the immune system. Researchers explain this attraction of opposites with the fact that the combination of different immune systems means a good defense for the offspring from an evolutionary point of view. In the latest odor study, however, the Bern researchers found no influence of these HLA genes. At least they played no part in judging the female scent. However - according to researcher Janek Lobmaier in the interview (see above) - the scents of women that were smelled by men were examined here. Most of the studies that find the genetic link are women who smell men.