"L-lysine is an essential free form amino acid, which acts as a precursor for several other amino acids, including l-citrulline needed in the body for normal protein metabolism and l-carnitine needed for fat metabolism .l-lysine is crucial to the formation of collagen, a major part of the body's connective tissues. L-lysine also contributes ato energy production when converted to acetyl coenzyme a, one of the principal fuels for the Krebs' cycle. Suitable for vegetarians and hypoallergenic."