From the Manufacturer's label
L-Arginine and L-Citrulline are two amino acids bundled into a single powerful supplement. L-Arginine is an important factor in muscle metabolism and is a precursor for nitric oxide, which promotes increased circulation by relaxing blood vessels.** L-Citrulline helps the body rid itself of ammonia, a by-product of exercise.**
Manufactured by Source NaturalsContains no yeast, dairy, egg, gluten, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance.