Male mice have a constant sex drive regardless of pain. The sex drive of female mice is curbed by pain. These are the results of the first known study of the relationship between pain and sexual behavior in any mammal species. The research was conducted by researchers from McGill University and Concordia University in Montreal and was reported in the April 22, 2014, edition of the Journal of Neuroscience.
Both male and female mice were exposed to a chemical that produced the same level of inflammation and pain. In one part of the study, male and female mice wee separated by a panel that was too small for the males to squeeze through. Female mice in heat were found to spend less time mating if the female mice experienced pain. The female mice that experienced pain escaped from the male mice by remaining in the part of the cage that the male mice could not access. Male mice did not present any evidence that pain inhibited their sex drive.
The female mice that experienced pain due to inflammation were found to return to a normal level of sexual behavior if they were given a pain-relieving drug or a desire-enhancing drug. Males needed no external stimulation despite pain. Mice are used in lab tests because mouse brain chemistry is equivalent to human brain chemistry.
Barring any other relationship issue, the research indicates that female’s sexual desire is more highly influenced by pain than males. If a woman says "Not tonight, dear, I have a headache" there is a chemical reason and not an excuse. The researchers propose an ancient evolutionary adaptation as the source of female’s higher sensitivity to pain when it comes to mating.
Females have been documented to have innate evolutionary controls on mating behavior. These controls are considered to promote mating with the most productive male at the most opportune time to produce offspring that have the highest potential for survival and continuation of the species. Feeling pain may be an evolutionary caution against mating in women.
The research has practical implications for women. A multitude of diseases and physical conditions produce constant pain. Women who feel pain constantly do not have a normal sex drive as indicated by the research. The study indicates a pathway that will allow women that experience chronic pain to enjoy desire and sex again.