Causes of weakened libido in men

Testosterone, an aphrodisiac and anabolic hormone

Testosterone is the hormone responsible for libido in both men and women. For testosterone to promote youthful sexual performance, interest and satisfaction, it must be freely available to the receptor sites of brain cells. 90% of testosterone is produced by the testicles, the rest by the adrenal glands. In brain cells, testosterone plays two roles. It acts as an aphrodisiac hormone but also as an anabolic hormone in the development of bones and skeletal muscles. Aging men often attribute the decrease in their sexual potency to testosterone deficiency but this is not the basic problem. The total testosterone level of men aged 50 to 70 is not much different from that of younger adults.

Free testosterones vs related testosterones vs libido

Testosterones therefore have two functions, that of anabolic and that of libido. Some of these bind to serum globulin (protein). By binding to this protein, it no longer becomes available to the sites of cell receptors that induce sexual desire.

The hormone that controls free testosterone levels is Sex Hormone Binding Globulin (SHBG). When testosterone binds to SHBG, it loses its biological activity and becomes a bound testosterone. With age, the amount of testosterone related to GBS increases in favor of those that are not, thereby decreasing sexual desire. The decline in interest in sex that occurs over the years is therefore not due to the amount of testosterone produced but rather to the increase in testosterone bonds with globulin through SGBH. In men, a simple and safe way to increase their free testosterone levels is to prevent its conversion into excess estrogen.