Testosterone is the main male sex hormone and an anabolic steroid. It plays a fundamental role in the development of male reproductive tissues, such as the testicles and the prostate , as well as in the promotion of secondary sexual characteristics, such as the increase in muscle mass , increase and maturation of bones and the growth of body hair. In addition, testosterone is involved in the health and well-being of people and in the prevention of osteoporosis .
Testosterone is synthesized mainly in male testicles and to a lesser extent by female ovaries in various stages from cholesterol . It is converted in the liver to inactive metabolites .
Testosterone use by women
About 40% of the middle-aged female population suffers from pain, discomfort, lack of excitement and libido and difficulty in reaching orgasm as part of a sexual dysfunction due to low testosterone. Testosterone deficiency in women has direct implications for both sexual dysfunction and decreased sexual desire. But, to start testosterone therapy, the patient must undergo an interview with a doctor , who will assess her health and sex life, in addition to doing a detailed physical examination.
The use of testosterone for a short period, up to 3 years, seems to be safe in previously healthy patients, from a hormonal point of view. However, there are no studies on the safety of using this hormone for longer periods. Several hypotheses of possible risks are raised: risks linked to thromboembolic events, liver diseases and the possibility of the appearance of some types of cancer .
Studies analyzing the risks of testosterone use and development of cancer of breast , of endometrial and ovarian not associated the hormone the largest incidence of these types of cancer . However, the Brazilian Society of Endocrinology and Metabology (SBEM) warns that there is still no scientific support to ensure the prescription of testosterone for long periods.
Read about ” Falling libido “, ” Hormone modulation ” and ” Hormone replacement therapy “.
Testosterone use by men
Since testosterone levels gradually decrease as men age, synthetic testosterone is often prescribed as a replacement for older men to counteract this deficiency. In the case of males, SBEM informs that the use of testosterone is only approved in Brazil for the treatment of male hypogonadism and, for a short term, for the recovery of cachexia . Misuse for muscle mass gain is considered doping in professional athletes and illegal in amateurs, and should not be done.
What is the physiological role of testosterone?
Testosterone, like other androgens , promotes protein synthesis and, thus, tissue growth with androgen receptors . It is described as a substance that has virilizing and anabolic effects . Anabolic effects include growth of muscle mass and strength, increased bone density and stimulation of linear growth and bone maturation. Androgenic effects include maturation of the sexual organs, formation of the scrotum in the fetus , thickening of the voice after birth and growth of facial and axillary hair.
The effects of testosterone before birth include genital virilization, scrotal wear, roughness and enlargement of the penis and the development of the prostate and seminal vesicles . During the second trimester of pregnancy , it is associated with gender formation, affecting the feminization or masculinization of the fetus . The mother’s testosterone level during pregnancy is correlated with the child’s sex and psychological behavior.
Androgenic effects during childhood are of little significance and little studied. Before puberty there is a small increase in androgen levels , both in boys and girls. Puberty effects start to occur when androgen levels increase. The effects then include, in addition to several other changes, growth of sperm tissue and male fertility, enlargement of the penis or clitoris, increased libido and the frequency of erections or engorgement of the clitoris. There is an increase in strength and muscle mass and the pubic hair extends to the thighs .
In adulthood, the effects of testosterone are clearer in men than in women, but they are probably equally important for both sexes. Testosterone is necessary for normal sperm development and activates genes in Sertoli cells , which promote sperm differentiation . It regulates the acute response of the hypothalamic- hypophyseal axis .
