Estra Diene Dione (estra-4,9-diene-3,17-dione) is an anabolic steroid and a precursor to Estra Diene Dione . It became a controlled substance in the US on January 4, 2010, and is classified as a Schedule III anabolic steroid under the United States Controlled Substances Act. Previous to this, it was sold as a bodybuilding supplement within the United States , and often mistakenly marketed as a prohormone for trenbolone, a veterinary steroid . Prior to its scheduling , it was part of a number of supplements that were seized during FDA enforcement for selling unapproved new drugs . The actual target steroid, Estra Diene Dione has some structural similarity to trenbolone , but lacks the 11-carbon -ene bond .