Overview

L-arginine is an amino acid that helps the body build protein.

Your body usually makes all the L-arginine it needs. L-arginine is also found in most protein-rich foods, including fish, red meat, poultry, soy, whole grains, beans and dairy products.

As a supplement, L-arginine can be used orally and topically.

Because L-arginine acts as a vasodilator, opening (dilating) blood vessels, many people take oral L-arginine to try to treat cardiovascular conditions and erectile dysfunction.

Evidence

Research on the use of L-arginine for specific conditions shows:

  • Angina. Studies suggest that L-arginine might decrease symptoms and improve quality of life in people with a mild to severe form of this type of chest pain.
  • High blood pressure (hypertension). Some research has shown that oral L-arginine can lower blood pressure in healthy people and people with a type of high blood pressure that affects the arteries in the lungs and the right side of the heart (pulmonary hypertension). Infusions of L-arginine also appear to reduce blood pressure in people with hypertension.
  • Erectile dysfunction. Taking oral L-arginine might improve sexual function in men with erectile dysfunction due to a physical cause.

Our take

Green light: Generally safe

Generally safe

L-arginine is considered to be generally safe and might be effective at lowering blood pressure, reducing the symptoms of angina and treating erectile dysfunction due to a physical cause.

However, if you take a blood pressure drug, talk to your doctor before using L-arginine.

Oct. 24, 2017