L-glutamine is the most prevalent amino acid in the blood. Human cells readily manufacture L-glutamine and under normal circumstances, dietary intake and production of L-glutamine is sufficient. However, in times of stress or increased energy output, the body’s tissues need more L-glutamine than usual, making supplementation important.

L-glutamine can be found in beans, brewer’s yeast, brown rice bran, dairy products, eggs, fish, legumes, meat, nuts, seafood, seeds, soy, whey, whole grains and beet root.

Dosage Info

Dosage Range

500-4,000mg, 3 times daily.

Oral rinse: 16gm in 240ml normal saline, swish and expectorate, 4 times a day (for radiation therapy-induced mucositis and chemotherapy-induced stomatitis).

Most Common Dosage

500-1,000mg, 3 times daily.

Dosage Forms

Powder, capsules, tablets, and liquid.

Interactions and Depletions


Reported Uses

One of L-glutamine’s most important functions involves the support of cellular energy, growth and repair. Studies suggest that alcoholics may lack the necessary systems to deliver L-glutamine to cells that are in need of it. In these cases, L-glutamine supplementation in concert with riboflavin may relieve symptoms of alcoholism. (1)

L-glutamine may have several applications in the treatment of cancer. First, scientists believe that L-glutamine may be deficient in patients with tumors and that supplementation may restore L-glutamine to normal levels. (2) What’s more, L-glutamine may reduce tumor growth. (3) Taking L-glutamine in an oral rinse preparation may also reduce the pain and inflammation associated with chemotherapy.

Scientists also believe that deficiency in L-glutamine may be linked to gastrointestinal disorders such as irritable bowel syndrome, Crohn’s disease, and colon inflammation. Supplementation may improve symptoms of these disorders while supporting overall health of the intestines. (4) , (5)

L-glutamine may also boost the immune system, some studies suggest. Scientists think that taking L-glutamine orally may enhance the activity of infection-fighting white blood cells and other agents. It may also decrease the permeability of the intestines, thus making it harder for invaders to attack the body. (6)

L-glutamine levels have been found to be decreased in endurance athletes who train too often and at high intensity. (7) , (8) In fact, these athletes tend to have a higher incidence of infectious diseases and allergies, and have been noted to have swollen lymph nodes and experience slower wound healing. Athletes undergoing a strenuous workout schedule may be able to reduce the risk of infections by supplementing with L-glutamine. (9) , (10) Athletes experienced an increase in body mass, lean body mass, and initial rate of power production when using a supplement containing creatine monohydrate and glutamine. (11)

Finally, because L-glutamine supports the growth of new cells, it may be useful in the enhancement of wound healing. Wounds such as burns, surgical and traumatic wounds, cuts, and others may heal faster with supplementation. (12) , (13)

Toxicities & Precautions


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This dietary supplement is considered safe when used in accordance with proper dosing guidelines.

Health Conditions

If you have liver failure, talk to your doctor before taking this dietary supplement. (14)

Side Effects

Occasional side effects reported with the use of this dietary supplement include diarrhea in rare cases. Tell your doctor if these side effects become severe or do not go away.

Pregnancy / Breast Feeding

To date, the medical literature has not reported any adverse effects related to fetal development during pregnancy or to infants who are breast-fed. Yet little is known about the use of this dietary supplement while pregnant or breast-feeding. Therefore, it is recommended that you inform your healthcare practitioner of any dietary supplements you are using while pregnant or breast-feeding.

Age Limitations

To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Since young children may have undiagnosed allergies or medical conditions, this dietary supplement should not be used in children under 10 years of age unless recommended by a physician.


  1. Bobrova NP, et al. Effect of chronic alcohol intoxication, termination of ethanol administration, and treatment of abstinence with glutamine and riboflavin on neuromediatory systems of gamma-aminobutyric acid and acetylcholine in the rat brain. Vopr Med Khim. Jan1982;28(1):103-6.
  2. View Abstract: Klimberg VS, McClellan JL. Glutamine, cancer, and its therapy. Am J Surg. 1996;172:418-424.
  3. View Abstract: Fahr MJ, Kornbluth J, Blossom S, et al. Harry M. Vars Research Award. Glutamine enhances immunoregulation of tumor growth. JPEN J Parenter Enteral Nutr. 1994;18:471-476.
  4. View Abstract: O’Keefe SJ. Nutrition and gastrointestinal disease. Scand J Gastroenterol Suppl. 1996;220:52-9.
  5. View Abstract: Fujita T, et al. Efficacy of glutamine-enriched enteral nutrition in an experimental model of mucosal ulcerative colitis. Br J Surg. Jun1995;82(6):749-51.
  6. View Abstract: Wells SM, et al. Dietary glutamine enhances cytokine production by murine macrophages. Nutrition. Nov1999;15(11-12):881-4.
  7. View Abstract: Shephard RJ, et al. Immunological hazards from nutritional imbalance in athletes. Exerc Immunol Rev. 1998;4:22-48.
  8. View Abstract: Castell LM, et al. Glutamine and the effects of exhaustive exercise upon the immune response. Can J Physiol Pharmacol. May1998;76(5):524-32.
  9. View Abstract: Nieman DC. Exercise and resistance to infection. Can J Physiol Pharmacol. May1998;76(5):573-80.
  10. View Abstract: Rhode T, et al. Glutamine, exercise, and the immune system–is there a link? Exerc Immunol Rev. 1998;4:49-63.
  11. View Abstract: Lehmkuhl M, Malone M, Justice B, et al. The effects of 8 weeks of creatine monohydrate and glutamine supplementation on body composition and performance measures. J Strength Cond Res. Aug2003;17(3):425-38.
  12. View Abstract: Demling RH, et al. Metabolic management of patients with severe burns. World J Surg. Jun2000;24(6):673-80.
  13. Houdijk AP, et al. Glutamine-enriched enteral nutrition in multiple trauma patients. Nutrition. Jan2000;16(1):70-1.
  14. View Abstract: Albrecht J, Dolinska M. Glutamine as a pathogenic factor in hepatic encephalopathy. J Neurosci Res. Jul2001;65(1):1-5.