HMB is an amino acid derived from the breakdown of leucine, a component of regular proteins. It can also be found in foods such as alfalfa and is a natural component of breast milk. HMB was discovered in the 1950s and has been studied for several decades, but it only became a sports supplement in 1995. HMB has been shown to slow the breakdown of muscle tissue while simultaneously promoting the growth of lean muscle mass. Studies indicate that HMB lowers cholesterol and helps strengthen the immune system. It is an active metabolite of the branched-chain amino acid leucine. HMB is a popular supplement in all Applied Nutrition products, usually taken post-workout. Instructions for use: For best results, take 2 capsules (1 serving) 1 to 3 times daily.