Description

Beta-methylbutryic acid, technically known as, "beta-hydroxy beta-methylbutyric acid," or more commonly known as "HMB," is a metabolite of the amino acid leucine. Human muscles have a particularly high concentration of leucine, so this amino acid is often broken down/utilized during strenuous exercise. HMB is also found in grapefruit and catfish in trace quantities. It was first found to be of use in agriculture as an additive to help pigs, chickens, and other farm animals gain muscle and lose fat. It was not until a research trial conducted by the University of Iowa at Iowa City showed positive results that it caught attention as promising for human use.

The four-week double-blind study in 1995 involved 17 exercise-trained and 23 untrained males, divided into two groups. One group took daily capsules containing 3g of HMB, and the...