Some bodybuilders and athletes use trenbolone for its muscle-building and otherwise performance-enhancing effects. [ citation needed ] Such use is illegal in the United States and many other countries. The DEA classifies trenbolone as a Schedule III controlled substance 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 .  The infamous "duchess" cocktail administered to Russian athletes at the Sochi Winter Olympics consisted of oxandrolone , metenolone , and trenbolone. 
As we discussed above, Dianabol carries a strong aromatizing nature, and is a C17-aa anabolic steroid; as such, its side-effects will revolve around these factors. As an aromatizing steroid, this means there can be a testosterone to estrogen conversion, and if estrogen levels go to high it can lead to some complications. When estrogen levels increase, the hormone can attach to the receptors and cause gynecomastia (male-breast enlargement) and it can also promote excess water retention and high blood pressure; Dbol is notorious for promoting high blood pressure. Needless to say, if you already suffer from high blood pressure you should not touch this steroid, but if it's healthy you'll need to ensure it stays this way. For this reason, in-order to combat and avoid these estrogenic side-effects of Dbol, the use of an Aromatase Inhibitor (AI) is often advised. It shouldn't be too hard to see how this can help; after all, an AI inhibits aromatase, but it goes a step further by reducing the body's total estrogen levels. Of course, and this cannot be overstressed, you must keep your doses at a responsible level; most will need at least 20mg per day for any anabolic promotion, with a maximum dosing of 50mg per day. It should be noted; if you've never used this steroid before, you should not start with a high end dose; start low and see how you respond.