Testosterone, or testosterone, is not related to the IQ tax and is a steroid hormone. Testosterone plays a role in many physiological processes and is an indispensable androgen in the body. Testosterone is secreted by the testes in men, the ovaries in women, and the adrenal glands. Most of testosterone is metabolized and inactivated by the liver. Testosterone affects many physiological functions of the body. 1. It affects embryonic sex differentiation: testosterone induces male genital development during fetal period and prompts the formation of the first male sex sign. 2. Testosterone can promote the development of male secondary sexual characteristics: such as, penis, scrotum growth, the emergence of male-specific physical characteristics of pubic hair, laryngeal bulge. Maintains libido. 3. Influence spermatogenesis: promote sperm production. 4. Affecting material metabolism: promoting protein synthesis, promoting bone growth, increasing bone density, maintaining muscle strength, accelerating the growth of the body. Testosterone is detrimental to lipid metabolism and increases the risk of cardiovascular disease in men. 5. Testosterone also stimulates erythropoiesis, etc.