L-LysineHelps reduce the recurrence of herpes simplex virus (HSV) infection Provides lysine, an essential amino acid that maintains good health Provides lysine, an essential amino acid that maintains good health. The essential amino acid L lysine cannot be synthesized by the body and must be supplied through the diet. It is best known for its ability to reduce the recurrence of infections caused by the herpes simplex virus (HSV), which mainly affects the skin