Lysine (abbreviated as Lys or K) is an a-amino acid. This amino acid is an essential amino acid, which means that humans cannot synthesize it. Lysine is a base, as are arginine and histidine.
L-Lysine is a necessary building block for all protein in the body. L-Lysine plays a major role in calcium absorption; building muscle protein; recovering from surgery or sports injuries; and the body’s production of hormones, enzymes, and antibodies.
It has been suggested that lysine may be beneficial for those with herpes simplex infections.