Some bodybuilders and athletes use trenbolone esters for their muscle-building and otherwise performance-enhancing effects.  Such use is illegal in the United States and many other countries. The DEA classifies trenbolone and its esters as Schedule III controlled substances under the Controlled Substances Act .  Trenbolone is classified as a Schedule 4 drug in Canada  and a class C drug with no penalty for personal use or possession in the United Kingdom .  Use or possession of steroids without a prescription is a crime in Australia . 
Since the drug is a derivative of dihydrotestosterone, which does not aromatize (not converted into estrogen, which causes side effects such as gynecomastia and fluid accumulation in the body).
Oxandrolone has no significant effect on the level of natural testosterone production in moderate doses (not inhibit the uptake mechanism of hypothalamic-pituitary-testes axis). When the dose is high, the body reacts to a decrease in gonadotropin production, suggesting that the endogenous testosterone level is too high. Lack of stimulation of Leydig cells leads to testicular atrophy. Oxandrolone is used in a dose of 80 mg per day suppresses testosterone levels after 12 weeks of 67%.