L-Lysine is an amino acid found in the protein of foods such as beans, cheese, yogurt, meat, milk, brewer’s yeast, wheat germ, and other animal proteins. Proteins derived from grains such as wheat and corn tend to be low in L-Lysine content. The bio availability of L-Lysine is reduced with food preparation methods, such as heating foods in the presence of a reducing sugar (ie, fructose or glucose); heating foods in the presence of sucrose or yeast; and cooking in the absence of moisture at high temperatures. The average 70 kg human requires 800 to 3,000 mg of L-Lysine daily.

L-Lysine is an essential amino acid in human nutrition because the body cannot produce it; therefore, it must be taken in either by diet or supplementation. L-Lysine was first isolated from casein (a milk phosphoprotein) in 1889. It was first introduced in the United States as L-Lysine hydrochloride in 1955. There was an interest in fortifying bread with L-Lysine to target populations with L-Lysine poor diets. However, the FDA refused to modify the standards of identity for white bread. Since 1970, L-Lysine has been commonly added to animal feed.

L-Lysine has been studied for the prevention and treatment of herpes infections and cold sores. It also increases the intestinal absorption of calcium and eliminates its excretion by the kidney, suggesting that it might be helpful in osteoporosis. L-Lysine has been investigated for its effects on increasing muscle mass, lowering glucose, and improving anxiety. Case reports suggest lysine may ameliorate angina. L-Lysine acetylsalicylate has been used to treat pain and to detoxify the body after heroin use. L-Lysine clonixinate has been used to treat migraine headaches and other painful conditions. However, limited clinical trials exist for these conditions.