After ejaculation, high levels of prolactin, the same hormone that makes breastfeeding possible, are concentrated in man and responsible for the fall in sexual desire.
From intense passion to deep sleep in a few minutes. One of the fastest biological transitions in man happens after intercourse: it is the refractory period, the “down” produced after orgasm, after ejaculating, and stretching until man is able to start another sexual relationship. It can last from a few minutes in younger men to up to a few hours. This phase is related to a complex set of hormones, including prolactin. The same hormone that makes breastfeeding possible is involved in about 300 biological processes, including the production of semen and also sexual desire.
Researcher Susana Lima of the Champalimaud for the Unknown Center, as part of her publication series Neurobiology of Sex, has observed this process in laboratory mice: “It is shocking to see how before ejaculation, the female is the most desired object and , Just after orgasm, is relegated to the background, “he explains. During different phases of the sexual behavior of the mice, their prolactin levels were measured and it was observed that, after orgasm and ejaculation, a peak occurs in prolactin levels in both sexes, which coincides with a decrease in sexual desire.
Evolutionarily, it can be explained as follows: since biologically the goal of ejaculation is reproduction, man will try to conserve the energies until he can mate with another female. A reserve phase attributed to prolactin. Despite this, there are still more studies that corroborate this. “One way to shorten the refractory period would be to introduce a new female,” explains the researcher. This would increase the level of other types of hormones, such as dopamine and adrenaline, and would reactivate sexual desire.
However, the relationship between prolactin and sexual desire has been established previously. Men who have a pituitary tumor experience an overproduction of prolactin, and that causes a decrease in sexual desire. The same thing happens to women who are breastfeeding, at which point prolactin levels increase.
So, could control over prolactin become the substitute for viagra? In theory, by consciously lowering prolactin levels we could manipulate, in this case increase, sexual desire. For Lima, prolactin seems to be a serious candidate. “At this time, we are blocking prolactin in the brain areas we know are important for sexual behavior and see which of these areas light up,” he explains. It remains to be seen exactly how much prolactin is involved in sexual desire.