Arginine (L-Arginine)

Medically Reviewed by Kathleen M. Zelman, RD, LD, MPH on March 23, 2023
3 min read

Arginine, or L-arginine, is an amino acid that is made in the body. As a supplement, it seems to help with several conditions, from migraines to inflammation. Your body typically makes all the L-arginine it needs and it is in most protein-rich foods such as fish, red meat, poultry, soy, whole grains, beans, and dairy products.

Why do people take arginine?

Because it relaxes blood vessels, arginine might have cardiovascular benefits for some people. Studies show that it might ease the symptoms of angina and peripheral arterial disease. It seems to boost the health of people with heart failure. It might also help with erectile dysfunction, but mostly when combined with other supplements such as pine bark extract. Some studies have shown an immune-boosting effect.

Arginine may also combat the symptoms of weight loss caused by HIV. It seems to improve the symptoms of kidney inflammation and assists kidney function after a transplant. Studies show arginine might ease migraines, improve blood pressure, and lessen recovery time after surgery.

Not all studies have been positive. Arginine does not seem to help with heart attack recovery, preeclampsia, wound healing, or exercise tolerance in people with heart failure. It seems to worsen asthma.

Arginine has been studied as a treatment for many more conditions. They include dementia, hypertension, cancer, male infertility, diabetes, and obesity. But the results have been inconclusive. More research needs to be done to substantiate all of the potential benefits.

Arginine has become a popular supplement in the U.S. However, most people seem to have enough arginine in their bodies already. They might not get many benefits from supplements. It can be taken orally, intravenously, or topically.

How much arginine should you take?

There is no standard dose of arginine. Studies have used different amounts for different conditions. One common dosage is 2 to 3 grams three times a day, although lower and higher doses have also been studied. The safety of long-term arginine supplement use is not clear. Ask your doctor for advice.

In some cases, doctors recommend supplemental arginine. People with protein malnutrition, burns, infections, rapid growth, and other conditions might benefit from supplemental arginine.

Can you get arginine naturally from foods?

Many foods are natural sources of arginine. They include nuts (like walnuts, hazelnuts, pecans, peanuts, almonds, cashews, and Brazil nuts), seeds (like sesame and sunflower), oats, corn, cereals, buckwheat, brown rice, dairy products, meat, chicken, and chocolate.

What are the risks of taking arginine?

  • Side effects. Most people taking arginine have few side effects. It can cause nausea, cramps, diarrhea, allergic reactions, and asthma symptoms. It could also cause low blood pressure and changes to glucose and blood chemical levels. There is some thought that the ratio of lysine to arginine in the diet (or with supplements) can affect whether or not latent herpes viruses appear. Some doctors recommend increasing lysine and decreasing arginine to help prevent the recurrence of symptoms associated with herpes simplex virus.
  • Risks. If you have any medical conditions -- like cancer, asthma, allergies, liver or kidney problems, low blood pressure, sickle cell disease, or a bleeding disorder -- or have had a heart attack, don't take arginine without talking to a doctor first.
  • Interactions. If you take any medicines or supplements regularly, talk to your doctor before you start using arginine. They could interact with birth control medicines, hormone therapy drugs, blood thinners, some painkillers, and medicines for erectile dysfunction, heartburn, high blood pressure, and diabetes. Arginine could also interact with supplements like ginkgo biloba, garlic, Asian ginseng, and potassium.

Given the uncertain risks, arginine should not be used by children or by women who are pregnant or breastfeeding without a doctor's approval.