L-Citrulline

A non-protein amino acid that is converted to arginine in the urea cycle. L-citrulline and citrulline salts are often added to NO (nitric oxide) boosters to enhance NO production.   Citrulline may be a better source of supplemental arginine than arginine itself. When taken together, arginine and citrulline work synergistically to enhance NO production and improve blood flow.