L-Lysine HCl supplies the essential amino acid L-lysine. L-Lysine has documented immuno-supportive properties, is important for proper growth, and it plays an essential role in the production of carnitine. Carnitine functions in assisting in the conversion of fatty acids into energy, and may also assist in normalizing cholesterol. Additionally, Lysine may aide in helping the body absorb calcium, and it plays an important role in the formation of collagen. Since Lysine and Arginine share common pathways in the body, high levels of arginine may lower lysine levels in the body.