Regulates Protein Breakdown In The Body! HMB (ß-Hydroxy ß-Methylbutyrate) is a clinically researched, naturally occurring metabolite of the branched-chain amino acid leucine. HMB normally plays a role in the regulation of protein breakdown in the body, helping to preserve lean muscle tissue. HMB therefore can help to maintain muscle strength and mass when combined with regular exercise and a healthy diet. In addition, it may help to enhance recovery from intense exercise. Note: Manufacturers continually change product specifications. While we try our best to keep product descriptions up to date, they do not necessarily reflect the latest information available from the manufacturer. We are not responsible for incorrect or outdated product descriptions and/or images.