HMB (short for β-Hydroxy β-Methylbutyrate) is a metabolite of the amino acid leucine  that, along with KIC (α keto-isocaproate) and isovaleryl-CoA, mediate the effects of leucine. Approximately 5% of dietary leucine is oxidized into HMB, and HMB appears to be the main metabolite of leucine that more effectively prevents the breakdown of muscle protein. When compared to leucine, HMB appears to …