Arginine for Weight Control
Also known as: L-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.
Why do dieters use it?*
Some dieters say that arginine
What do the advocates say?*
When used while weight training, a combination of arginine and ornithine have been found to
decrease body fat, resulting in higher strength and leaner muscle. Be aware, when
supplementing with individual amino acids, it’s possible to upset the body’s
balance of amino acids by taking just one.
How much is usually taken by dieters?
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?
For most people, arginine has so far appeared to be free of obvious side effects. However,
longer-term studies are needed to confirm its safety.
In a double-blind study, supplementation with 9 grams of arginine per day for six months,
beginning within 3 to 21 days after a heart
attack, resulted in an increase in the mortality rate.6 Therefore, people who
have recently suffered a heart attack should probably not take large amounts of arginine.
Arginine is beneficial for other manifestations of heart disease, such as heart failure and
angina. However, because of the potential for arginine to cause adverse effects in heart
patients, people with heart disease should consult a doctor before taking arginine.
There have been two case reports of severe allergic reactions following intravenous
administration of L-arginine;7 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
promote8 and to interfere with
cancer growth.9 In preliminary research, high intake (30 grams per day) of
arginine has increased cancer cell growth in humans.10 On the other hand, in people
with cancer, arginine has been found to stimulate the immune system.11 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.
*Dieters and weight-management 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. Schulman SP, Becker LC, Kass DA, et al. L-arginine therapy in acute
myocardial infarction: the Vascular Interaction With Age in Myocardial Infarction (VINTAGE MI)
randomized clinical trial. JAMA 2006;295:58–64.
7. Resnick DJ, Softness B, Murphy AR, et al. Case report of an
anaphylactoid reaction to arginine. Ann Allergy Asthma Immunol
2002;88:67–8.
8. Park KGM. The immunological and metabolic effects of L-arginine in
human cancer. Proc Nutr Soc 1993;52:387–401.
9. 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.
10. Park KGM. The immunological and metabolic effects of L-arginine in
human cancer. Proc Nutr Soc 1993;52:387–401.
11. Brittenden J, Park KGM, Heys SD, et al. L-arginine stimulates host
defenses in patients with breast cancer. Surgery 1994;115:205–12.