In the body, the amino acid arginine changes into nitric oxide. Nitric oxide is a powerful neurotransmitter that helps blood vessels relax and also improves circulation.
Therefore, arginine may help to increase your ability to exercise and may improve symptoms such as shortness of breath and tiredness. It works by relaxing and widening the blood vessels (arteries) in the lungs, muscles, and other parts of the body so that blood can flow more easily.
It has also been shown to improve blood flow in the arteries of the heart, and improve sexual function in men and women.