HMB is an amino acid, but derives from the breakdown of Leucine, a part of normal dietary protein. HMB can be also found in certain foods like catfish, alfalfa and it is also a natural component of mother’s milk, but is scarcely found in a normal diet. HMB was discovered in the 1950’s and has been studied for several decades, but has only really become popular as a sports supplement around 1995. HMB has been proven to slow down the breakdown of muscle protein as well as promote lean gains, which means that it has both tissue sparing and tissue building qualities. Early studies have shown that HMB supplementation also lowers cholesterol and helps strengthen the immune system.