The amino acid l-arginine plays an important role in the cardiovascular system L-arginine is the only substrate for the production of nitric oxide, which is primarily responsible for vasodilation. Here lies the benefit of L-arginine and its effects on the cardiovascular system. Arginine interacts with the blood to regulate blood flow and regulate pressure inside vessels - L-arginine acts as an anti-aggregation or anti-coagulant in blood vessels and as an anti-hemolytic