Lysine

Lysine provides additional benefits of immune support and collagen synthesis beyond suppressing cold sore outbreaks. Cold sores are caused by the herpes simplex virus, which lies dormant in nerve tissue and reactivates periodically. Lysine suppresses herpes simplex viral reactivation by competing with arginine, which the virus requires to replicate. Best dietary sources of lysine include parmesan cheese, turkey, chicken, and fish.