L-arginine is important for vision because it is a nitric oxide precursor. The body needs low levels of nitric oxide for a number of functions, including keeping blood vessels dilated and flexible and supporting kidney functioning. L-arginine is used to build protein in the body. L-arginine generally supports vision indirectly, that is, through its ability to improve blood flow, improve sugar balance, and remove waste ammonia from the body.

Inflammation. L-arginine's important role in vision health is underlined by its capacity as an anti-inflammatory agent. Inflammation and resulting oxidative stress increase the risk of many eye conditions and health conditions.1

Diabetic retinopathy. As a result of insufficient blood circulation to the retina, diabetic retinopathy is a common complication of type 2 diabetes. L-arginine stimulates the creation of insulin by the pancreas, improving (but not normalizing) insulin sensitivity in patients.

Glaucoma. In one study, administered through an intravenous drip infusion, l-arginine reduced intraocular pressure significantly, and then the IOP increased again fairly rapidly. The test does not therefore suggest that this amino acid improves glaucoma problems, but that it lowered IOP primarily through the formation of nitric oxide. 3

Related disorders. In the body, l-arginine is converted into nitric oxide, which expands blood vessels. So, it plays a role in supporting the heart and circulatory system, including maintenance of normal blood pressure. It may be helpful for angina and leg pain that is due to poor blood flow because it dilates blood vessels; but it, itself, does not help cardiovascular conditions.7

L-arginine may be helpful in reducing high blood pressure. A review of the research indicates, overall, that it improves endothelium-derived nitric oxide production and function on endothelium cells, which line blood vessels and reduce systemic blood pressure in some models of hypertension. 4

L-arginine helps the body get rid of waste products, such as ammonia, and supports kidney functioning. It is essential to maintain nitric oxide levels needed for proper kidney functioning. Patients with kidney failure have low levels of l-arginine in the blood.5


  • Combined with other drugs, it is used in treating a number of conditions ranging from migraines to cancer.
  • Combined with other amino acids, it is used in treating side effect weight loss.
  • Combined with ribonucleic acid and an omega-3 fatty acid, eicosapentaenoic acid, it improves healing of wounds.
  • L-arginine also naturally stimulates the release of other enzymes and hormones in the body, such as insulin and growth hormone

Food sources. Arginine is available through nuts, poultry, red meat, fish, and dairy products, as well as grains, beans, corn, and leafy-green vegetables.

Caution. People who are prone to allergies or asthma should take l-arginine with caution, as it may increase airway swelling. It may make herpes worse, should not be taken to prevent a heart attack, or by people with kidney disease. Because it can interfere with blood pressure, it should not be taken at least two weeks before surgery.6

Foot notes

1. Morais SRL, Brito VGB, Mello WG, Oliveira SHP. (2018). L-arginine modulates inflammation and muscle regulatory genes after a single session of resistance exercise in rats. Scand J Med Sci Sports. Feb;28(2):425-435.
2.Piatti, P.M., Monti, L.D., Valsecchi, G., Magni, F., Setola, E., et al. (2001). Long-Term Oral l-Arginine Administration Improves Peripheral and Hepatic Insulin Sensitivity in Type 2 Diabetic Patients. Diabetes Care, May; 24(5): 875-880.
3. Chuman, H., Chuman, T., Nao-i, N., Sawada, A. (2000). The effect of L-arginine on intraocular pressure in the human eye. Curr Eye Res, Jun;20(6):511-6.
4. Gokce, N. (2004). L-Arginine and Hypertension. J Nutr, Oct 1:134(10) 28075-115.
5. Brunini, T.M., da Silva, C.D., Siqueria, M.A., Moss, M.B., Santos, S.F., et al. (2006). Uremia, atherothrombosis and malnutrition: the role of L-arginine-nitric oxide pathway. Cardiovasc Hematol Disord Drug Targets, Jun;6(2):133-40.
6. L-Arginine. WebMD. Retrieved Nov 1 2017 from https://www.webmd.com/vitamins-supplements/ingredientmono-875-l-arginine.aspx.
7. Sudar-Milovanovic E, Obradovic M, Jovanovic A, Zaric B, Zafirovic S, et al. (2016). Benefits of L-Arginine on Cardiovascular System. Mini Rev Med Chem. 2015;16(2):94-103.

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