Androgenic anabolic steroids (AAS) are widely used by athletes, bodybuilders and adolescents for performance enhancement. They are either consumed orally or by injection. More than 100 different AAS are used illegally. The aim of the present study was to compare alkylating and non-alkylating AAS effects on the liver, immune system and reproductive system. Anabol, nandrolone and both drugs stacked were used in therapeutic, low toxic and high toxic doses. 374 adult male albino rats (~100-120gms) were divided into 3 groups (128 each) according to drug used, and then subdivided into 3 subgroups (32 each) according to dose. Drugs were given for 3 months then discontinued for an extra month to allow for recovery. At the end of each month, the rats were weighed, blood samples collected and tissues obtained for histopathological examination. The results of the present study revealed affected liver functions in the form of increased AST, ALT, total proteins, albumin and GSH, while MDA showed no change. It should be noted that oral steroids showed maximum effects. However, IgG and IgM revealed maximum elevation with the oral and maximum depression with the injectable AAS. Testosterone hormone decreased maximally in the stack-treated rats. Affection was maximum in G3 of the 3rd period. Recovery occurred in the 4th period but normalization was incomplete. Histopathology confirmed these changes.