All in the nose?

Researchers from the University of Texas at Austin have established that men find that women smell particularly pleasant during the fertile periods of their menstrual cycle. Seventeen women participated in the study which was designed to establish what sort of odour a woman gives off at different times of her cycle, especially when she ovulates. Women have massive hormonal changes during their menstrual cycles, and it is thought that body odours change with hormone level changes.

The women were asked to wear one T-shirt for three nights during the most fertile phase of their cycle, and another shirt during their least fertile period. They were not allowed to wash using perfumed soaps, or use perfumes, eat spicy foods, use the contraceptive pill, or have sex.

A group of 52 men were then given the shirts to smell and rate in terms of how intense, how pleasant and how sexy they thought each shirt smelled. The striking results showed that the men found the T-shirts worn by women in their fertile phase to smell nicer, even sexier, than the others.

The results fit with other studies that suggest that a woman's body sends out multiple signals to men when she is fertile. For example, it is thought that the skin lightens and that the breasts become more symmetrical during a woman's most fertile period.