Nevertheless there is enough evidence of the toxic effects of steroids. And recent studies indicate that that the drugs affect the brain reward systems. Withdrawal systems are well documented. Steroids have been linked to pathologies of the cardiovascular, immune, endocrine, psychiatric, reproductive and urogenital systems. Steroid abuse can also lead to liver disease and cancer, and inreased risk of injury to tendons, ligaments and muscles.
Men can experience atrophy of the testes, reduced sperm count, and abnormal breast growth.
Anabolic-androgenic steroids are synthetic analogs of the endogenous steroid hormone testosterone. Testosterone is a member of the androgen family of steroid hormones, one of six families of mammalian steroid hormones. The other five are estrogens, progestins, mineralcorticoids, glucocorticoids, and vitamin D with its metabolites. Like all steroids, androgens, testosterone included, are biologically derived from cholesterol. Cholesterol and all steroids consist of a phenanthrene ring structure with a pentano ring attached.