Glutamine is the most abundant amino acid (building block of protein) in the body. The body can make enough glutamine for its regular needs, but extreme stress (the kind you would experience after very heavy exercise or an injury), your body may need more glutamine than it can make. Most glutamine is stored in muscles followed by the lungs, where much of the glutamine is made.
Glutamine is important for removing excess ammonia (a common waste product in the body). It also helps your immune system function and appears to be needed for normal brain function and digestion.
You can usually get enough glutamine without taking a supplement, because your body makes it and you get some in your diet. Certain medical conditions, including injuries, surgery, infections, and prolonged stress, can lower glutamine levels, however. In these cases, taking a glutamine supplement may be helpful.
Woundhealing and recovery from illness
When the body is stressed (from injuries, infections, burns, trauma, or surgical procedures), it releases the hormone cortisol into the bloodstream. High levels of cortisol can lower your body’s stores of glutamine. Several studies show that adding glutamine to enteral nutrition (tube feeding) helps reduce the rate of death in trauma and critically ill people. Clinical studies have found that glutamine supplements strengthen the immune system and reduce infections (particularly infections associated with surgery). Glutamine supplements may also help in the recovery of severe burns.
Inflammatory bowel disease (IBD)
Glutamine helps to protect the lining of the gastrointestinal tract known as the mucosa. For that reason, some have suggested that people who have inflammatory bowel disease (ulcerative colitis and Crohn’s disease) may not have enough glutamine. However, 2 clinical trials found that taking glutamine supplements did not improve symptoms of Crohn’s disease. More research is needed. In the meantime, ask your doctor when deciding whether to use glutamine for IBD.
People with HIV or AIDS often experience severe weight loss (particularly loss of muscle mass). A few studies of people with HIV and AIDS have found that taking glutamine supplements, along with other important nutrients including vitamins C and E, beta-carotene, selenium, and N-acetylcysteine, may increase weight gain and help the intestines better absorb nutrients.
Athletes who train for endurance events (like marathons) may reduce the amount of glutamine in their bodies. It’s common for them to catch a cold after an athletic event. Some experts think that may be because of the role glutamine plays in the immune system. For this select group of athletes, one study showed that taking glutamine supplements resulted in fewer infections. The same is not true, however, for exercisers who work out at a moderate intensity.
Many people with cancer have low levels of glutamine. For this reason, some researchers speculate that glutamine may be helpful when added to conventional cancer treatment for some people. Supplemental glutamine is often given to malnourished cancer patients undergoing chemotherapy or radiation treatments and sometimes used in patients undergoing bone marrow transplants. (See Interactions below.)
Glutamine seems to help reduce stomatitis (an inflammation of the mouth) caused by chemotherapy. Some studies, but not all, have suggested that taking glutamine orally may help reduce diarrhea associated with chemotherapy.
More clinical research is needed to know whether glutamine is safe or effective to use as part of the treatment regimen for cancer.
Dietary sources of glutamine include plant and animal proteins such as beef, pork and poultry, milk, yogurt, ricotta cheese, cottage cheese, raw spinach, raw parsley, and cabbage.
Glutamine, usually in the form of L-glutamine, is available by itself or as part of a protein supplement. These come in powder, capsule, tablet, or liquid form.
Standard preparations are typically available in 500 mg tablets or capsules.
Take glutamine with cold or room temperature foods or liquids. It should not be added to hot beverages because heat destroys glutamine.
For children 10 years and younger: Do not give glutamine to a child unless your doctor recommends it as part of a complete amino acid supplement.
For adults ages 18 and older: Doses of 500, 1 - 3 times daily, are generally considered safe. Doses as high as 5,000 - 15,000 mg daily (in divided doses), or sometimes higher, may be prescribed by a health care provider for certain conditions.
Because of the potential for side effects and interactions with medications, you should take dietary supplements should be taken only under the supervision of a knowledgeable health care provider.
Glutamine appears to be safe in doses up to 14 g or higher per day, but you should only take doses this high under the supervision of a health care provider.
Glutamine powder should not be added to hot beverages because heat destroys this amino acid. Glutamine supplements should also be kept in a dry location.
People with kidney disease, liver disease, or Reye syndrome (a rare, sometimes fatal disease of childhood that is generally associated with aspirin use) should not take glutamine.
Many elderly people have decreased kidney function and may need to reduce the dose of glutamine.
Glutamine is different from glutamate (glutamic acid), monosodium glutamate, and gluten. Glutamine should not cause symptoms (headaches, facial pressure, tingling, or burning sensation) associated with sensitivity to monosodium glutamate. People who are gluten sensitive can use glutamine without problems. However, some people may be sensitive to glutamine, which is completely separate from gluten.
If you are currently being treated with any of the following medications, you should not use glutamine supplements without first talking to your health care provider.
Cancer therapy -- Some people suggest that glutamine may increase the effectiveness and reduce the side effects of chemotherapy treatments with doxorubicin, methotrexate, and 5-fluorouracil in people with colon cancer. Preliminary clinical studies suggest that glutamine supplements may prevent nerve damage associated with a medication called paclitaxel, used for breast and other types of cancers.
However, laboratory studies suggest that glutamine may actually stimulate growth of tumors. Much more research is needed before it is known whether it is safe to use glutamine if you have cancer. If you are receiving chemotherapy, you should never add supplements to your regimen without consulting your physician.
Abcouwer SF. The effects of glutamine on immune cells [editorial]. Nutrition. 2000;16(1):67-69.
Agostini F, Giolo G. Effect of physical activity on glutamine metabolism. Curr Opin Clin Nutr Metab Care. 2010; 13(1):58-64.
Akobeng AK, Miller V, Stanton J, Elbadri AM, Thomas AG. Double-blind randomized controlled trial of glutamine-enriched polymeric diet in the treatment of active Crohn's disease. J Pediatr Gastroenterol Nutr. 2000;30(1):78-84.
Antoon AY, Donovan DK. Burn Injuries. In: Behrman RE, Kliegman RM, Jenson HB, eds. Nelson Textbook of Pediatrics. Philadelphia, Pa: W.B. Saunders Company; 2000:287-294.
Avenell A. Symposium 4: Hot topics in parenteral nutrition Current evidence and ongoing trials on the use of glutamine in critically-ill patients and patients undergoing surgery. Proc Nutr Soc. 2009 Jun 3:1-8. [Epub ahead of print]
Buchman AL. Glutamine: commercially essential or conditionally essential? A critical appraisal of the human data. Am J Clin Nutr. 2001;74(1):25-32.
Clark RH, Feleke G, Din M, et al. Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy-beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind placebo-controlled study. JPEN: J Parenter Enteral Nutr. 2000;24(3):133-139.
Daniele B, Perrone F, Gallo C, et al. Oral glutamine in the prevention of fluorourcil induced intestinal toxicity: a double blind, placebo controlled, randomized trial. Gut. 2001;48:28-33.
Decker GM. Glutamine: indicated in cancer care? Clin J Oncol Nurs. 2002;6(2):112-115.
Fan YP, Yu JC, Kang WM, Zhang Q. Effects of glutamine supplementation on patients undergoing abdominal surgery. Chin Med Sci J. 2009 Mar;24(1):55-9.
Field CJ, Johnson IR, Schley PD. Nutrients and their role in host resistance to infection. J Leukoc Biol. 2002 Jan;71(1):16-32.
Furukawa S. Saito H, Inoue T, et al. Supplemental glutamine augments phagocytosis and reactive oxygen intermediate production by neutrophils and monocytes from postoperative patients in vitro. Nutrition. 2000;1695):323-329.
Garlick PJ. Assessment of the safety of glutamine and other amino acids.J Nutr. 2001 Sep;131(9 Suppl):2556S-61S. [Review].
Greenlee H, Hershman DL, Jacobson JS. Use of antioxidant supplements during breast cancer treatment: a comprehensive review. Breast Cancer Res Treat. 2009 Jun;115(3):437-52. Epub 2008 Oct 7.
Grimm H, Kraus A. Immunonutrition--supplementary amino acids and fatty acids ameliorate immune deficiency in critically ill patients. Langenbecks Arch Surg. 2001 Aug;386(5):369-376.
Lecleire S, Hassan A, Marion-Letellier R, Antonietti M, Savoye G, et al. Combined glutamine and arginine decrease proinflammatory cytokine production by biopsies from Crohn's patients in association with changes in nuclear factor-kappaB and p38 mitogen-activated protein kinase pathways. J Nutr. 2008 Dec;138(12):2481-6.
Medina MA. Glutamine and cancer. J Nutr. 2001;131(9 Suppl):2539S-2542S; discussion 2550S-2551S.
Murray SM, Pindoria S. Nutrition support for bone marrow transplant patients. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD002920. Review.
Neu J, DeMarco V, Li N. Glutamine: clinical applications and mechanism of action. Curr Opin Clin Nutr Metab Care. 2002;5(1):69-75
Rakel D. Integrative Medicine, 2nd ed. Philadelphia, PA: Saunders, An Imprint of Elsevier; 2007.
Reeds PJ, Burrin DG. Glutamine and the bowel. J Nutr. 2001;131(9 Suppl):2505S-8S.
Vahdat L, Papadopoulos K, Lange D, et al. Reduction of paclitaxel-induced peripheral neuropathy with glutamine. Clin Cancer Res. 2001;7(5):1192-1197.
van Stijn MF, Ligthart-Melis GC, Boelens PG, Scheffer PG, Teerlink T, et al. Antioxidant enriched enteral nutrition and oxidative stress after major gastrointestinal tract surgery. World J Gastroenterol. 2008 Dec 7;14(45):6960-9.
Weitzel L, Wischmeyer P. Glutamine in Critical Illness: The Time Has Come, The Time Is Now. Critical Care Clinics. 2010;26(3).
Wilmore DW. The effect of glutamine supplementation in patients following elective surgery and accidental injury. [Review]. J Nutr. 2001;131(9 Suppl):2543S-9S; discussion 2550S-1S.
Ziegler TR. Glutamine supplementation in cancer patients receiving bone marrow transplantation and high dose chemotherapy. [Review]. J Nutr. 2001;131(9 Suppl):2578S-84S; discussion 2590S.