Objective. To develop the understanding of side effects of anabolic agents during unapproved use by athletes.
Methods. Analysis of the data of scientific-methodical literature and Internet.
Results. The paper presents the results of the analysis of current literature dealing with metabolic pathways of anabolic steroid influence on the increase of indices of physical work capacity and sports performance, and describes the main representatives of the class of androgenic anabolic steroids and other banned anabolic agents. The paper also addresses the modern technologies for detection anabolic steroids in an athlete's body during doping control. Wide spectrum of side effects of steroids in athletes of different ages is identified. Side effects are categorized according to the direction of their impact on the physiological systems of the body.
Conclusion. The widest spectrum of anabolic steroid side effects according to «harm/benefit» criterion gives good reasons to include them in WADA Banned List and requires attention on the part of sports and medical community in order to prevent steroid usage by athletes, especially young, that may reduce quality of life and increase the risk of fatalities.