L-Lysine is an essential amino acid that is a necessary building block for all protein in the body, and it is found in large amounts in muscle tissue. Lysine plays an importantrole in calcium absorption, building muscle protein, recovering from injuries, and the production of hormones of the body, enzymes and antibodies.

Lysine also helps in the formation of collagen, which supports the skin, muscles and joints. Lysine may be beneficial for those with herpes simplex infections. When taking L-arginine, it is advisable to also use lysine otherwise it may stimulate the replication of the herpes virus if you have it. Lysine can be paired with other growth hormone releasing aminos like arginine on an empty stomach before training or going to bed.