Arginine lowers blood pressure

Arginine is a conditionally essential amino acid (which sometimes has to be supplied through food) that is popular with bodybuilders because it stimulates the release of growth hormone and nitric oxide production. Growth hormone promotes muscle hypertrophy and stimulates metabolism, while nitric oxide increases blood flow. Arginine could also lower blood pressure by improving endothelial function.
A Polish study of men suffering from mild hypertension (high blood pressure) found that four weeks of arginine supplementation (6 to 12 grams per day) lowered systolic and diastolic blood pressure by 2 to 6 points (1 to 3 percent). The supplement likely works by improving the health of the cell lining of the arteries (endothelium) and increasing the capacity of these cells to release nitric oxide.
L-arginine could be a good supplement for bodybuilders and other weight-training athletes because it improves blood flow to muscles, lowers blood pressure and increases growth hormone levels.
(Medicine Science Monitor, 16: CR266-271, 2010)