Arginine (L-Arginine) Overview: What is Arginine?

L-arginine, or arginine, is one of the 22 amino acids. Amino acids are small molecules that are building blocks of proteins. Arginine is a precursor to several important metabolites, including nitric oxide. In the body, L-arginine is converted into a chemical known as nitric oxide. Nitric oxide opens the blood vessels, which improves blood flow. L-arginine also increases the production of growth hormone, insulin, and other hormones in the body. It can be synthesised in a laboratory and used in supplements. In addition, L-arginine can improve erectile function in males with erectile dysfunction. Thus, nitric oxide is crucial for proper erection and blood flu. (1, 2).

What Is L-Arginine Used For?

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Some studies assert that L-arginine is used to treat chest pain, heart conditions, erectile dysfunction, high blood pressure during pregnancy, and necrotizing enterocolitis (NEC), a serious disease that affects premature infants. It’s also used by some people to boost their immune systems, improve energy and performance, reduce recovery time after surgery, and promote weight loss. However, there’s no concrete scientific evidence to back up these claims.(3, 4, 5, 6, 7, 8)

Side Effects

When taking L-arginine as a supplement, you should know about its potential side effects. These include:

  • increased risk of bleeding
  • unhealthy imbalance of potassium
  • change in blood sugar levels
  • decreased blood pressure
  • bloating and abdominal pain
  • allergies or worsening of asthma

Take L-arginine with caution if you are also taking prescription ED medications such as sildenafil (Viagra) or tadalafil (Cialis). L-arginine may cause your blood pressure to drop, so if you have low blood pressure or take blood pressure medications, avoid it or consult a doctor before trying it. If you experience ED symptoms, consult your doctor. Most times, ED results from an underlying medical condition. Stress and interpersonal problems are also concerns for many males.

Related article: L-tyrosine supplements for erectile dysfunction


Recommended daily dosage of arginine is dependent and can range from 5 to 24 grams taken orally per day. People who are taking medications prescribed by their doctor will continue to take those medications and definitely check with your doctor before using arginine supplements. Also, speak with a healthcare provider to determine what sort of product or dose is best for a particular problem.

Can I get L-arginine naturally?

One advantage of getting L-arginine through diet is that you can prevent negative effects of taking too much. Animal proteins, such as red meat (beef), chicken, turkey breast, and dairy products, are the primary source of L-arginine. For people who don’t eat meat can include plant-based arginine sources such as lentils, chickpeas, peanuts, pumpkin seeds, and soybeans. People who don’t get enough L-arginine may want to include more protein-rich foods to their diet. Prior to taking supplements, a dietitian or doctor may give food plan recommendations to increase natural consumption of L-arginine.

Can pregnant women take arginine?

Studies show that arginine-derived nitric oxide can support a particular hypertension called pre-eclampsia, and can prevent premature labor and premature birth. However, pregnant women should speak to their doctor before adding any supplements to their diet. (9)


Arginine has a very excellent safety profile and seems to have nearly no toxic effects. From that point of view, things get much less clear. Early studies suggested it might boost growth hormone. In reality, they discovered these effects using very high doses. There was an intravenous and temporary spike in GH. However, it does not have beneficial effects on healthy people.

Suggested article: Health benefits of citrulline supplements


  1. Effects of 7 days of arginine-alpha-ketoglutarate supplementation on blood flow, plasma L-arginine, nitric oxide metabolites, and asymmetric dimethyl arginine after resistance exercise. Int J Sport Nutr Exerc Metab. 2011.
  2. Levels of l-arginine and l-citrulline in patients with erectile dysfunction of different etiology. Andrology. 2017.
  3. Role of l-Arginine in Oligohydramnios. J Obstet Gynaecol India. 2016.
  4. L-Arginine Therapy in Acute Myocardial Infarction: The Vascular Interaction With Age in Myocardial Infarction (VINTAGE MI) Randomized Clinical Trial. JAMA. 2006.
  5. Effect of l-arginine, asymmetric dimethyl arginine, and symmetric dimethyl arginine on ischemic heart disease risk: A Mendelian randomization study. American Heart Journal, Volume 182, 2016.
  6. Role of Arginine and Omega-3 Fatty Acids in Wound Healing and Infection. Advances in Wound Care Vol. 3, 2014.
  7. Pre-exercise arginine supplementation increases time to exhaustion in elite male wrestlers. Biol Sport. 2014.
  8. Effect of supplementation during pregnancy with L-arginine and antioxidant vitamins in medical food on pre-eclampsia in high-risk population: randomised controlled trial. BMJ 2011.
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Naeem Durrani BSc
I am a retired pharmacist, nutrition expert, journalist, and more. My interests include medical research, and the scientific evidence around effective wellness practices, which empower people to transform their lives.

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