IntroductionAnabolic androgenic steroids (AAS) are known to be misused both in competitive and in non-competitive sports (Haupt and Rovere 1984; Wilson 1988; Yesalis et al. 1993). Moreover, it seems that AAS are becoming “social drugs”, as even young people apply them as an expression of an improved “life-style”.The misuse of AAS in athletics has been observed for more than 40 years. The first rumours dated from 1954 and were attributed to weightlifters who seemed to have used testosterone (Wade 1972). By 1965 synthetic AAS had become widely popular among bodybuilders and weightlifters, but were also applied in other forms of sports.By using these steroids athletes hoped to increase muscle strength. Such improvements in muscle strength to increase physical performance in sport are naturally an essential effect of training. As AAS stimulate protein synthesis in muscle cells, athletes expect performance-enhancing effects beyond that brought about by training alone. At the end of the sixties the first anti-doping rules were established by international sport federations (1967 International Cycling Union, UCI, and 1968 International Olympic Committee, IOC), but only stimulants and narcotics were banned (Clasing 1992). At that time the Medical Commission (MC) of the IOC was already aware of widespread misuse of AAS in sports. They were not banned because no reliable method was available to detect them (Beckett and Cowan 1979).