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. 
This should give you a good understanding of tren and how perfect of a compound it is when you’re choosing which AAS to run. In most cases tren should not be run by itself; tren will shut down your natural testosterone production and you’re best suited to stack tren with some form of testosterone. Also, an important note, Trenbolone is typically not suitable for beginners; Trenbolone as we can see is a very, very potent compound and the side effects in some cases can be brutal for some lifters. That is also another reason why Trenbolone Acetate is best in comparison to other forms of Trenbolone. Because it has the Acetate ester attached to it, making it very fast acting and giving it a very short half-life, if problems arise, the lifter can discontinue Trenbolone Acetate and have it cleared from his system very quickly.
Unfortunately, the same study that tells us that MENT is 10x as anabolic as testosterone, and 4x as androgenic, also tells us that MENT is 12x as suppressive to serum gonadatropins as testosterone. For this reason, it is very appealing to scientists who have studied it for use as a male contraceptive – and ended up calling it “ The Optimal Androgen for Male Contraception ” (Ann Med. 1993 Apr;25(2):199-205.). In addition, and partly owing to its inability to be 5a-reduced, MENT is converted (via the aromatase enzyme) to a very potent form of estrogen – which can cause gynecomastia (enlarged breast tissue in males), and several other nasty side effects.