L-Lysine HCl provides the essential amino acid L-lysine. L-lysine has documented immune-supportive properties, is important for proper growth, and plays a critical role in the production of carnitine. Carnitine aids in the conversion of fatty acids into energy and can also help normalize cholesterol. Additionally, lysine can help the body absorb calcium and plays an important role in collagen formation. Since lysine and arginine share common pathways in the body, high levels of arginine can lower lysine levels in the body.