Stanozolol is a derivative of dihydrotestosterone, chemically altered so that the hormone’s anabolic (tissue-building) properties are greatly amplified and its androgenic activity minimized. Stanozolol is classified as an “anabolic” steroid, and exhibits one of the strongest dissociations of anabolic to androgenic effect among commercially available agents. It also cannot be aromatized into estrogens. Stanozolol is the second most widely used oral steroid, succeeded in popularity only by Dianabol (methandrostenolone).lt is favored for its ability to promote muscle growth without water-retention, making it highly valued by dieting bodybuilders and competitive athletes. Stanozolol is a modified form of dihydrotestosterone. It differs by the addition of a methyl group at carbon 17alpha to protect the hormone during oral administration and the attachment of a pyrazol group to the A-ring, replacing the normal 3-keto group (this gives stanozolol the chemical classification of a heterocyclic steroid).When viewed in the light of 17-alpha methyldihydrotestosterone, the A-ring modification on stanozolol seems to considerably increase its anabolic strength while reducing its relative androgenicity.