A non-protein amino acid that’s a precursor to carnosine (beta-alanyl-l-histidine). Carnosine is a dipeptide that’s highly concentrated in muscle tissue. It has antioxidant effects, and acts to buffer hydrogen ions produced during exercise, thus delaying muscle fatigue. Beta-alanine is marketed primarily as a bodybuilding, performance enhancing-supplement. See Paul’s review of H+Blocker, for more information.