L-Arginine: Overview

L-Arginine is a naturally-occurring "non-essential" amino acid.

Diagnose your symptoms now!
  • see your health summarized and in detail
  • let The Analyst™ find what's wrong
  • learn what you should be doing right now


L-Arginine is supplied in 500mg and 1,000mg capsules as well as a powder (1 teaspoon equals 4,000mg).  It is found in various bars and other products.

Function; Why it is Recommended

Arginine works as a precursor for endothelial cell releasing factor (ECRF), now thought to be nitric oxide.  It is a substance produced by one's own blood vessels that keeps the blood vessel open (vasodilatation) rather than spastically closed (vasoconstriction), dilating the coronary and other arteries.

Arginine has received favorable reports in preventing and treating heart disease, cancer and infection.

Arginine is a 'regenerative' in that it promotes growth hormone production, slows down the growth of tumors and cancer by supporting and enhancing the immune system, promotes improved immune system responses to bacteria, viruses and tumor cells, supports healing, and is used in the treatment of AIDS and immune system diseases.  Arginine has been found to be useful in treating sterility in men.

Arginine may prevent angina (chest pain due to coronary vasoconstriction) or a heart attack.  Working on the peripheral arterioles, it is used to treat or prevent heart failure (the inability of the heart as a pump to keep up with the bodily needs of supply).  It has been exceedingly helpful in peripheral arterial disease in which the leg does not get enough blood for the exercising muscle, resulting in leg cramps.  L-Arginine prevents the build-up of cholesterol plaque and clots within all of our blood vessels.

Arginine may help release our growth hormone, the naturally rejuvenating hormone.  It also may promote sexual function, keep blood pressure normalized, improve coordination and long term memory and enhance our sense of smell.  Arginine might improve insulin sensitivity in Syndrome X and Type II Diabetes.

Arginine is also is a free radical scavenger, not only internally but externally, thus causing an anti-aging effect on the skin and the internal organs.  Additionally, Arginine has been shown to stimulate the immune function in several animal studies.  It has been used in combination with traditional approaches for the treatment of cancer, particularly cancer of the breast.  In an article from The University of Minnesota, oral L-Arginine in doses of 3gm twice a day taken with meals was recommended.


Although we get 5-6gm of this natural chemical from foods such as meat (including chicken) and nuts, to do the job well we need an additional 6gm each day.


This is an extremely safe product and the only side-effect ever described in an overdose of L-Arginine was mild diarrhea.  It is best to split the dose into 3gm twice per day.  Some doctors recommend up to 12gm per day.

References & Further Information

A comprehensive list of foods and their lysine/arginine content can be found here.

On This Page


L-Arginine can help with the following:


Poor/Slow Wound Healing

Injury significantly increases the need for the amino acid arginine, which is essential for a variety of metabolic functions.  In a clinical study published in a major medical journal, arginine supplementation significantly increased the amount of reparative collagen synthesized at the site of a "standard wound" (an incision 5cm long and 1mm in diameter) made in healthy volunteers.  The same study found marked enhancement of the activity and efficacy of peripheral T-lymphocytes (white blood cells in the bloodstream) [Kirk et al. 1993].

Other animal and human studies have demonstrated that arginine stimulates the cell-mediated immune response and protects against bacterial challenges [Gurbuz et al. 1998].  Arginine's ability to improve wound healing and immune-system function is thought to be related to its stimulation of the release of growth hormone.  Growth hormone plays a critical role in modulating the immune system and is essential for muscle growth and development.  That growth hormone secretion diminishes progressively with advancing age is one of the primary reasons for the decline in immune-system function and muscular strength as we grow older.

Under normal conditions, the 5gm per day of arginine found in the typical Western diet would be marginally sufficient to maintain tissue health.  Research has demonstrated, however, that in patients undergoing gallbladder surgery, supplementing 15gm of arginine for 3 days prior to surgery significantly reduced nitrogen excretion (evidence that the patients were using, not excreting, amino acids in order to heal) when compared with patients receiving conventional nutritional support.  In patients undergoing surgery for gastrointestinal cancer, supplementation with 25gm of arginine a day for 7 days improved their nitrogen balance as measured 5-7 days after surgery and led to more rapid recovery and discharge from the hospital. [Daly et al. 1995]

Intermittent Claudication

Intravenous injections of the amino acid arginine have been shown to be remarkably effective at improving intermittent claudication.  In a double-blind trial, 8gm of arginine, injected twice daily for three weeks, improved pain-free walking distance by 230% and absolute walking distance by 155%, compared to no improvement with placebo. [Boger RH, Bode-Boger SM, Thiele W, et al. Restoring vascular nitric oxide formation by L-arginine improves the symptoms of intermittent claudication in patients with peripheral arterial occlusive disease. J Am Coll Cardiol 1998;32: pp.1336-44]


Oral administration of L-arginine (700mg qid during continuous transdermal nitroglycerin therapy) increased treadmill walking time until the onset of moderate angina in a small well-controlled trial. [J Am Coll Cardiol 2002;39(7): pp.1199-203]


Not recommended for
Herpes Simplex Type I

Arginine promotes viral replication of herpes.  In some people, changing the dietary ratio of lysine to arginine reduces the frequency and intensity of outbreaks.

A comprehensive list of foods and their lysine/arginine content can be found here.


Erectile Dysfunction (ED, Impotence)

L-Arginine is the primary source of nitrous oxide (NO), an odorless gas made of nitrogen and oxygen that relaxes muscles and increases blood flow to organs – including the heart and penis.  By facilitating blood flow through the erectile tissue of the penis, NO produced from L-arginine can give men erections that are bigger, harder and more frequent.

In a group of 15 men with erectile dysfunction given 2,800mg of arginine per day for two weeks, six were helped, though none improved while taking placebo.  Although little is known about how effective arginine will be for men with erectile dysfunction or which subset of these men would be helped, available research looks promising and suggests that at least some men are likely to benefit. [Int J Impot Res 6: pp.33-6, 1994]

The dose can range from 1 to 3gm with meals, or up to 15gm about 45 minutes before sexual activity.  Arginine is not recommended if you have diabetes, arthritis, cancer, shingles, herpes I (fever blisters, cold sores) or herpes II.


Not recommended for
Herpes Simplex Type II

Arginine promotes viral replication of herpes.  In some people, changing the dietary ratio of lysine to arginine reduces the frequency and intensity of outbreaks.  Foods that are lower in lysine and higher in arginine such as chocolate, peanuts and other nuts, grains, peas, seeds, oatmeal and whole-wheat products should be reduced or eliminated from the diet.  Lists of foods and their lysine-to-arginine content are available on the Internet.

A comprehensive list of foods and their lysine/arginine content can be found here.

Tumors, Malignant

Cancer, General

Clinical studies have shown improved immune function in cancer patients fed arginine.


Interstitial Cystitis

Arginine, 3gm per day in divided doses on an ongoing basis, can reduce symptoms.  In some people with herpes, the arginine may need to be offset with lysine.  The body also uses arginine to make nitric oxide, which helps to relax smooth muscles like those found in blood vessels and the bladder.  Based on this known mechanism, arginine has been proposed as a treatment for various conditions that may be caused by limited blood flow.  Some researchers theorize that arginine's effects on nitric oxide synthesis might help relax the bladder, making it a useful treatment for IC.

Concerned or curious about your health?  Try The Analyst™
Symptom Entry
Symptom Entry
Full Explanations
Optional Doctor Review
Review (optional)


May be useful: may help with
May be useful:
may help with
Moderately useful: often helps with
Moderately useful:
often helps with
Often counterindicated: is often not recommended for
Often counterindicated:
is often not recommended for
We use cookies for traffic analysis, advertising, and to provide the best user experience