Shop products for Arginine 
What is it?
The amino acid arginine has several roles in the body, such as assisting in wound healing, helping remove excess ammonia from the body, stimulating immune function, and promoting secretion of several hormones, including glucagon, insulin, and growth hormone.
Where is it found?
Dairy, meat and poultry, and fish are good sources of arginine. Nuts and chocolate also contain significant amounts of this amino acid.
What do the advocates say?*
Arginine is a vasodilator; in other words, it increases blood flow so the heart can pump more blood at a lower level. Theoretically, this translates into improved cardiovascular performance. However, more research needs to be done to see if arginine supplementation can enhance athletes’ abilities to perform aerobic activities.
Be aware, when supplementing with individual amino acids, that it is possible to upset the body’s total balance of amino acids by taking just one.
How much is usually taken by athletes?
At very high intakes (approximately 250 mg per 2.2 pounds of body weight), the amino acid arginine has increased growth hormone levels,1 an effect that has interested body builders due to the role of growth hormone in stimulating muscle growth.2 However, at lower amounts recommended by some manufacturers (5 grams taken 30 minutes before exercise), arginine failed to increase growth hormone release and may even have impaired the release of growth hormone in younger adults.3
Double-blind trials conducted by one group of researchers, combining weight training with either arginine and ornithine (500 mg of each, twice per day, five times per week) or placebo, found the amino-acid combination produced decreases in body fat,4 resulted in higher total strength and lean body mass, and reduced evidence of tissue breakdown after only five weeks.5
Are there any side effects or interactions?
Arginine has so far appeared to be free of obvious side effects. However, longer-term studies are needed to confirm its safety.
There have been two case reports of severe allergic reactions following intravenous administration of L-arginine;6 however, allergic reactions have not been reported after oral administration.
People with kidney or liver disease should consult their doctor before supplementing with arginine. Some doctors believe that people with herpes (either cold sores or genital herpes) should not take arginine supplements, because of the possibility that arginine might stimulate replication of the virus.
Administration of large amounts of arginine to animals has been found both to promote7 and to interfere with cancer growth.8 In preliminary research, high intake (30 grams per day) of arginine has increased cancer cell growth in humans.9 On the other hand, in people with cancer, arginine has been found to stimulate the immune system.10 At this time it remains unclear whether arginine is dangerous or helpful for people with cancer.
Arginine works with ornithine in the synthesis of growth hormone.
At the time of writing, there were no well-known drug interactions with arginine.
*Athletes and fitness advocates may claim benefits for arginine based on their personal or professional experience. These are individual opinions and testimonials that may or may not be supported by controlled clinical studies or published scientific articles on arginine. For more complete and detailed information, including references and safety information, see Arginine as a nutritional supplement.
References
1. Besset A, Bonardet A, Rondouin G, et al. Increase in sleep related GH and Prl secretion after chronic arginine aspartate administration in man. Acta Endocrinol 1982;99:18–23.
2. Macintyre JG. Growth hormone and athletes. Sports Med 1987;4:129–42 [review].
3. Marcell TJ, Taaffe DR, Hawkins SA, et al. Oral arginine does not stimulate basal or augment exercise-induced GH secretion in either young or old adults. J Gerontol A Biol Sci Med Sci 1999;54:M395–9.
4. Elam RP. Morphological changes in adult males from resistance exercise and amino acid supplementation. J Sports Med Phys Fitness 1988;28:35–9.
5. Elam RP, Hardin DH, Sutton RA, et al. Effects of arginine and ornithine on strength, lean body mass and urinary hydroxyproline in adult males. J Sports Med Phys Fitness 1989;29:52–6.
6. Resnick DJ, Softness B, Murphy AR, et al. Case report of an anaphylactoid reaction to arginine. Ann Allergy Asthma Immunol 2002;88:67–8.
7. Park KGM. The immunological and metabolic effects of L-arginine in human cancer. Proc Nutr Soc 1993;52:387–401.
8. Takeda Y, Tominga T, Tei N, et al. Inhibitory effect of L-arginine on growth of rat mammary tumors induced by 7,12-dimethlybenz(a)anthracine. Cancer Res 1975;35:2390–3.
9. Park KGM. The immunological and metabolic effects of L-arginine in human cancer. Proc Nutr Soc 1993;52:387–401.
10. Brittenden J, Park KGM, Heys SD, et al. L-arginine stimulates host defenses in patients with breast cancer. Surgery 1994;115:205–12.
