Unflavored Power Nitric Oxide Booster Amino Acid L-arginine supplements may enhance exercise performance by increasing nitric oxide in the body, which improves blood flow and oxygenation to muscles. L-arginine supplements may benefit those with high blood pressure. Studies have shown that taking L-arginine supplements may help lower both your systolic (the top number) and diastolic (the bottom number) blood pressure readings. L-arginine is needed for the production of nitric oxide, which is necessary for the relaxation of the cells that make up blood vessels, as well as blood pressure regulation.