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. It can also be administered intravenously (IV).

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