MP, also known as 6α-methyl-17α-hydroxyprogesterone or as 6α-methyl-17α-hydroxypregn-4-en-3,20-dione , is a synthetic pregnane steroid and a derivative of progesterone .   It is specifically a derivative of 17α-hydroxyprogesterone with a methyl group at the C6α position.   The generic name of MP is a contraction of 6α- me thyl-17α-hy droxyprogesterone . It is closely related to medrogestone as well as other unesterified 17α-hydroxyprogesterone derivatives such as chlormadinone , cyproterone , and megestrol .  
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.