Steroids can have long-lasting and sometimes irreversible side effects on the body. Anabolic steroids have been linked to increased cholesterol, stroke and blood clots, urinary and bowel problems, and problems with the musculoskeletal system. Since steroids are a hormone, much like testosterone, the effects on sex characteristics can be far reaching, causing a kind of hyper-masculinity in young men. They can also cause male-pattern baldness and shrinking of the testicles. The excess of testosterone can also have feminizing effects on young men, such as breast development. (Jerry Adler, 2004)
Anabolic processes tend toward "building up" organs and tissues . These processes produce growth and differentiation of cells and increase in body size, a process that involves synthesis of complex molecules . Examples of anabolic processes include the growth and mineralization of bone and increases in muscle mass. Endocrinologists have traditionally classified hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The classic anabolic hormones are the anabolic steroids , which stimulate protein synthesis, muscle growth, and insulin .  The balance between anabolism and catabolism is also regulated by circadian rhythms , with processes such as glucose metabolism fluctuating to match an animal's normal periods of activity throughout the day.