L-arginine is a chemical building block called "an amino acid." It is obtained from the diet and is necessary for the body to make proteins. L-arginine is found in red meat, poultry, fish, and dairy products. While not exactly an “essential” amino acid — meaning an amino acid that the body cannot make on its own and, therefore, must get from outside sources —. L-arginine is considered somewhat essential because it’s highly important for many functions yet usually present in low quantities, especially as someone gets older.

How does it work?

L-arginine is converted in the body into a chemical called Nitric Oxide. NO improves circulation by dialing blood vessels, so when people don’t have enough in their arteries their risk for heart disease is higher.

NO keeps your blood pressure level within a normal range by signaling blood vessel muscles to relax, expand and let blood through, while also preventing clots and plaque from forming. Research suggests that as someone ages, his or her ability to produce enough NO in the artery linings decreases, but luckily obtaining more L-arginine — either through supplemental arginine or dietary arginine — can enhance nitric oxide capabilities and correct impaired endothelial function. This has multiple benefits, including improving immune function, fertility, detoxification, and brain power.

Another important aspect of L-arginine is that it stimulates the production of certain hormones, especially beneficial growth hormones and insulin that help usher glucose into cells to be used for growth and energy output. This is one of the reasons it’s believed to enhance physical performance, stamina and strength.

Other L-arginine benefits include:

  • Fighting inflammation
  • Lowering risk for arteriosclerosis and heart attack
  • Repairing blood vessels
  • Fighting congestive heart failure and coronary artery disease
  • Helping lower high blood pressure
  • Improving athletic performance
  • Increasing immune function
  • Reducing muscle pains (especially in the legs caused by blocked arteries)
  • Improving kidney function
  • Improving mental capacity
  • Fighting dementia
  • Correcting impotence, erectile dysfunction and male infertility
  • Preventing the common cold
  • Chest pain (angina)
  • High blood pressure
  • High blood pressure during pregnancy (pre-eclampsia)

Researchers found L-arginine levels decreased with aging, which in turn affected NO production. The benefits of L-arginine go beyond producing NO to help with circulation, however. As you’ll see, it has important roles in nerve signaling, cell replication and fighting oxidative stress that results in disease and signs of aging.

Are You Getting Enough L-arginine?

Everyone produces some L-arginine on his or her own, but how much depends on factors like your age, inflammation level, condition of your heart and arteries, gender, diet quality, and genetics. Some of the reasons someone might not produce optimal levels of L-arginine include eating a vegetarian/vegan diet low in complete protein sources, having poor digestive health that makes metabolizing protein difficult, high levels of oxidative stress caused by free radicals (due to diet, stress or pollution), smoking and genetic factors.

To naturally help your body make and use more L-arginine and nitric oxide, focus on eating a diet based on whole, real foods — especially “clean” sources of protein, which provide a full range of amino acids.