Any practice that involves putting blood into the body or taking blood our can be a serious risk to health. An athlete using their own blood runs the risk of bacterial infections, fatal reactions due to blood mislabeling and other complications including stroke, congestive heart failure, hypertension and blood clots. Steroids have been banned from every level of athletic competition for many years. The reason for banning steroids, outside of the fact that it gives athletes an unfair edge over their competition, is the physical and psychological harm it does to the body. Some physical side effects for men are impotence, urinating pain, development of breasts, and shrinking of testicles.
Women risk the danger of developing facial hair, a deepened voice, and menstrual cycle changes.
Both men and women can develop clotting disorders, liver damage, premature heart attacks and strokes, and elevated cholesterol. This is why steroids are banned from athletic competition, for the safety of the athletes. Creatine is legal, but so were steroids at one time. Creatine gives an athlete an edge over another athlete not using creatine for a simple reason. Creatine allows the body to replenish ATP sources quicker, thus allowing a person to exercise longer without fatigue and to recover faster.