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 .  The infamous "duchess" cocktail administered to Russian athletes at the Sochi Winter Olympics consisted of oxandrolone , a metenolone ester, and a trenbolone ester. 
Oral trenbolone is incredibly hepatotoxic, and even short cycles can take a toll. For this reason, most people prefer injectable Tren steroids. If you are interested in avoiding injections, though, and you want to use Tren oral, use the smallest possible dose that provides results for the shortest period possible. Be sure to also incorporate some liver protection into your cycle, whether you choose to use milk thistle or a specially-formulated liver care product. Overall, though, the consensus is that both oral and injectable Tren provide the same results at the same doses.