Anabolic steroids are synthetic derivatives of testosterone modified to enh
ance the anabolic rather than the androgenic actions of the hormone. The an
abolic effects are considered to be those promoting protein synthesis, musc
le growth and crythopoiesis. There are numerous side-effects to anabolic st
eroids, including hypertension and atherosclerosis, blood clotting, jaundic
e, hepatic carcinoma, tendon damage, psychiatric and behavioural effects an
d, in males, reduced fertility and gynaccomastia. Anabolic steroids were ad
ded to the International Olympic Committee's list of banned substances in 1
975. The majority of 'evidence' concerning the efficacy of anabolic steroid
s as performance enhancing agents is anecdotal. In the main, experimental i
nvestigations have been poorly designed scientifically, clinically and stat
istically. The percentage of positive test results from IOC accredited labo
ratories has remained consistently low. However, athletes take their steroi
ds during training and out-of-competition testing is not conducted in all c
ountries, although international co-operation is now under consideration. D
espite the lack of conclusive evidence, steroids users will continue to hol
d the view that their effects are efficacious and they are therefore unlike
ly to be persuaded to curtail their use.