L- Arginine 1000 mg Nitric Oxide Precursor for Vascular Support* Promotes Immune Function* Supports Muscle Metabolism* The amino acid L-Arginine has several major functions in the body, including as a precursor of nitric oxide (NO).This chemical messenger plays a vital role in vasodilatation, relaxation of smooth muscle cells within arterial blood vessels. Dietary L-Arginine provides the nitrogen our bodies use to produce NO. Because L-Arginine's potential role in vasodilatation, it may support healthy blood vessels.* Emerging evidence suggests a role of L-Arginine in immune function. It is well known that the body uses more L-Arginine when it is under stress or injured. Further, L-Arginine is also used by the body to produce creatine which supports muscle protein synthesis.* No Yeast, Wheat, Corn, Milk, Egg, Soy, Glutens, Artificial Colors or Flavors. Added Sugar, Starch or Preservatives. 100% Vegetarian