Lysine

Figure 1. The chemical structure of L-Lysine.

Lysine is an alpha-amino acid that is a precursor to many proteins in the human body. Lysine plays several roles in humans, most importantly proteinogenesis, but also in the crosslinking of collagen polypeptides, uptake of essential mineral nutrients, and in the production of carnitine, which is key in fatty acid metabolism. Lysine can be thought of as "a building block" for making proteins in the body.

The human body cannot synthesize Lysine, thus it is an essential nutrient. Good sources of Lysine are high-protein foods such as eggs, red meat, lamb, pork, poultry, soy, beans and peas, cheese, cod, and sardines.

As a dietary supplement, Lysine is often available in the stable form of L-Lysine hydrochloride (i.e. the hydrochloride salt of L-Lysine, the L-isomer of Lysine). Lysine is promoted to help with treatment of cold sores, reduce anxiety, improve calcium absorption and retention, and promote formation of Collagen.