Do Women's Tears Lower Testosterone?

Noam Sobel found that sniffing women's emotional tears lowers free testosterone by about 14 percent within about 20 minutes to half an hour, even though the tears are completely odorless.

His lab harvested emotional tears and had participants sniff them. Men and women smelling women's tears detected no odor at all, and free testosterone still fell by about 14 percent. People who study testosterone described the drop as very strong, and hard to produce that fast with a drug. Andrew Huberman, drawing on years spent studying endocrine effects, called the size of the effect tremendous. A concern was that the effort required to run the study meant nobody would try to replicate it. About two years later an independent group from South Korea replicated the testosterone drop with the same numbers. Measures of brain activity then showed a pronounced dampening during an arousing state, in the hypothalamus and in the fusiform gyrus, a face-recognition area. After the human work, a paper in Nature found a closely matching pattern in mice: mouse pup tears lower aggression from adult male mice in a smell-dependent way, and the researchers identified the tear component that does it.

The pattern frames tears as a chemical blanket, a signal that covers the person crying and protects against aggression.