What is lysine?

What is lysine ()? Lysine is an essential amino acid. Essential means that it is not produced by the body and therefore it must be taken in either by diet or by taking supplements. Lysine is found in foods such as yogurt, fish, cheese, brewer's yeast, wheat germ, pork, and other meats.Lysine has been used to treat or prevent herpes infections (genital herpes and cold sores) and canker sores. It has also been used to treat symptoms of Bell's palsy, and to improve calcium use in the body.Lysine has not been approved by the FDA to treat any disease, and it should not be substituted for prescription medications.Lysine may also have uses other than those listed in this product guide.