The results will be published in June in the journal Biology of Reproduction and currently appear on the journal's Web site.
"It has long been recognized that female pheromones can affect the menstrual cycles of other women," said George Preti, a member of the Monell Center and adjunct professor of dermatology in Penn's School of Medicine. "These findings are the first to document mood and neuroendocrine effects of male pheromones on females."
In a study led by Preti and colleague Charles J. Wysocki, extracts from the underarms of male volunteers were applied to the upper lip of 18 women ages 25 to 45. During the six hours of exposure to the compound, the women were asked to rate their mood using a fixed scale.
"Much to our surprise, the women reported feeling less tense and more relaxed during exposure to the male extract," said Wysocki, a member of the Monell Center and adjunct professor of animal biology in Penn's School of Veterinary Medicine. "This suggests that there may be much more going on in social settings like singles bars than meets the eye."
After the women's exposure to the underarm extract, further testing revealed a shift in blood levels of luteinizing hormone. Levels of this reproductive hormone, produced in pulses by the pituitary gland, typically surge right before ovulation but also experience hundreds of smaller peaks throughout the menstrual cycle.
Preti and Wysocki found that application of male underarm secretions hastened onset of these smaller pulses. Duration to the
Contact: Steve Bradt
University of Pennsylvania