L-Lysine Free Form L-Lysine is an essential amino acid which acts as a precursor for several other amino acids, including L-citrulline (needed in the body for normal protein metabolism) and L-carnitine (needed for fat metabolism). L-Lysine is crucial for the formation of collagen, a major part of the body's connective tissues. L-Lysine also contributes to energy production when converted to acetyl coenzyme A, one of the principal fuels for the Krebs cycle.* 500 mg Capsule Option Available: 100, 200 Suggested Use: 1 to 2 capsules daily. Allergies: HYPOALLERGENIC: contains no yeast, dairy, egg, gluten, corn, soy, or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor, or fragrance.