L Citrulline vs. L Arginine For Harder Erections (Pick Carefully!) Citrulline vs. Arginine Which One's Better for Vasodilation? @moreplatesmoredates A lot of pre workouts still include Arginine under the assumption that since it's the direct precursor to nitric oxide, it must be L Citrulline vs L Arginine: The Right Amino Acid for Formula Schematic presentation of the role of L citrulline L arginine cycle in Download Scientific Diagram