OstroVit - Histidine is an amino acid...
BioTech food supplement - HMB is an organic acid, an amino acid derivative, namely a metabolite of an important amino acid - L-leucine.
Nutritional supplement Nutriversum - HMB Basic - calcium hydroxymethyl butyrate (HMB), is an organic amino acid that is formed in the body during the breakdown of the amino acid leucine, which is part of the BCAA.