ʟ-lysine is one of the nine essential amino acids required for good nutrition and health.
ʟ-lysine is one of the many amino acids the body needs for tissue growth and repair. It is classified as one of the nine "essential" amino acids, because our bodies do not produce any. Like all amino acids, lysine is a constituent of proteins. It also plays a role in the production of various enzymes, hormones and disease-fighting antibodies.
Lysine supplementation increases calcium absorption and may reduce its excretion. As a result, some researchers believe that lysine may play a role in the prevention and treatment of osteoporosis. Lysine works with other essential amino acids to maintain growth, lean body mass and the body's nitrogen stores.