Amino acid supplements are usually based on either the full spectrum of the 9 essential amino acids, the branch chain amino acids (BCAA’s) or leucine on its own. Leucine is widely considered to be the key amino acid regarding muscle hypertrophy as without enough present, the other amino acids cannot bond to form the chains which go on to make up muscle tissue. Also very popular as a supplement are BCAA’s, of which leucine is the major component. Research on BCAA’s which are comprised of leucine, iso-leucine and valine, has shown that they are anti-catabolic in that they can actually prevent muscle breakdown. This makes them of particular benefit when used whilst training to protect muscle tissue and start the recovery process before training has ceased. All 9 essential amino acids have also been found to be of benefit in supplemental form, particularly when taken with meals to boost the amino acid content of the food which allows the body to make better use of the whole protein that has been consumed.
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.