When people associate a hormone with sex drive, they almost all think of testosterone, and for good reason. Testosterone is the hormone with the greatest impact on men’s sexual motivation, and its absence is often a direct cause of sexual dysfunction. But as important as testosterone is, it is not the only hormone responsible for regulating a man’s sex drive. For women, it is not testosterone that manages motivation for sex at all, but estrogens and progesterone, the workings of which are not completely understood. The lesser-known hormones oxytocin and vasopressin play a major role as well. The relationship between hormones and sexual motivation is complicated, and while testosterone is certainly a protagonist in this story, it is far from the only character.
Research has shown the testosterone plays a major role in increasing the sex drive of human males (and all male primates). When testosterone levels decrease, men show less inclination for sexual activity, including masturbation. Higher testosterone levels, meanwhile, bring a greater increase in sexual desire. Amazingly, there is significant evidence suggesting that men’s testosterone levels increase when they are in the presence of ovulating women, thereby creating circumstances more apt for procreation. It should be noted that testosterone does not make sexual intercourse possible for men, but it increases a man’s desire to partake in it.
While women’s bodies also produce testosterone, there is much less evidence that the presence of the hormone is responsible for sexual motivation. Studies of female primates, so similar in their sexual functioning to people, suggest that testosterone in of itself does very little, or perhaps nothing, to boost a women’s sex drive.
The Other Hormones that Affect a Person’s Sex Drive
For women, it seems that estrogen is the main hormone responsible for increasing sex drive, while high levels of progesterone decrease sexual desire. The levels of these two hormones in a woman’s body change during the menstrual cycle. When a woman is ovulating, and therefore most fertile, her body creates more estrogen and less progesterone. This makes sense from an evolutionary perspective, as it compels women to seek sexual intercourse when it is most likely to result in procreation. A number of studies have shown how women feel more sexual desire during the periovulatory phase of their menstrual cycle. Ovulating women, with a preponderance of estrogen in their systems, feel a greater attraction toward male faces than during other periods of their cycle because their estrogen levels are higher and their progesterone levels are lower. Women also experience a decrease in sexual motivation after menopause, a period that is also characterized by a significant decrease of estrogen in the body.
Oxytocin is another hormone that plays a pivotal role in sexual motivation for both men and women. It is the hormone that is released during orgasm, and, as such, it is essential for the pleasure we associate with sexual intercourse and the deep emotional bonds that sex often creates. For both men and women, a major motivator to have sex is that fact that it feels good. We owe this pleasure to oxytocin.
Vasopressin is a mysterious hormone with an interesting role to play in human sexual motivation, unique in that it seems to have an opposite effect on men and women. Higher levels of vasopressin in women are associated with an increase in aggression. This, in turn, brings a decrease in sexual motivation, perhaps because a hostile attitude is created toward a potential sexual partner. For men, however, vasopressin is associated with the increase in desire that comes with the formation of an erection. After ejaculation, a man’s vasopressin levels decrease, along with the man’s sexual desire.
The science of sex is complicated, and we certainly have a lot more to learn. What we know for now is that while testosterone plays a major role in increasing a man’s sex drive, but there are other hormones that have their own role to play. For women, it is not testosterone that stokes sexual desire, but estrogen. And for people of both sexes, it’s the sudden release of oxytocin at the moment of orgasm that gives sex its sensual allure. As for vasopressin, it seems to be a sexual stimulant for men and a turn-off for women. We might be a long ways from truly understanding the effects of hormones on human sexuality, but, from what science can already tell us, it’s safe to conclude testosterone is far from the only sex hormone. Call us at (205) 352-9141.