Advanced Nutrition by Zahler Freeform L-Lysine Potent Lysine Supplement General Health Dietary Supplement Feel Better, Everyday Kosher Pareve This Product was Manufactured in a GMP Certified Facility Gluten Free Soy Free Dairy Free Potent Lysine Supplement Lysine is an essential amino acid, which means the body requires it, but cannot produce it on its own. In addition to supporting the production of collagen, Lysine is commonly used to help to support the body's natural healing process.