Anavar is a Dihydrotestosterone derivative , which prevents it from interacting with the aromatase enzyme, which is the enzyme responsible for the conversion of androgens into Estrogen. As a result, one can expect very solid lean muscle gains without any water retention, and minimal fat gain/retention (provided the user has accompanied their cycle with an appropriate diet). Due to Anavar’s anabolic rating of 322 – 630 (the strength of at least 3 times that of Testosterone ), it can and will also elicit dramatic strength gains and considerable lean mass addition.
Anabolic steroids are synthetic derivatives of testosterone . Certain clinical effects and adverse reactions demonstrate the androgenic properties of this class of drugs. Complete dissociation of anabolic and androgenic effects has not been achieved. The actions of anabolic steroids are therefore similar to those of male sex hormones with the possibility of causing serious disturbances of growth and sexual development if given to young children. Anabolic steroids suppress the gonadotropic functions of the pituitary and may exert a direct effect upon the testes .
The drug was prescribed to promote muscle regrowth in disorders which cause involuntary weight loss, and is used as part of treatment for HIV/AIDS . It had also been shown to be partially successful in treating cases of osteoporosis . However, in part due to bad publicity from its illicit use by bodybuilders , production of Anavar was discontinued by Searle Laboratories in 1989. It was picked up by Bio-Technology General Corporation, which changed its name to Savient Pharmaceuticals , which following successful clinical trials in 1995, released it under the tradename Oxandrin.  BTG subsequently won approvals for orphan drug status by the Food and Drug Administration for treating alcoholic hepatitis , Turner syndrome , and HIV-induced weight loss . It is also indicated as an offset to protein catabolism caused by long-term administration of corticosteroids .