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Glutamine

Glutamine

While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.

Related Terms

  • 2,5-Diamino-5-oxopentaenoic acid, 2-aminoglutaramic acid, alanyl-glutamine, Aminopure™, D-glutamine, Dipeptiven®, Earthlink Science Glutamine Chews Chocolate (Amerifit), GLN, glutamic acid 5-amide, Glutamine Express (Genetic Evolutionary Nutrition), Glutamine Fuel Mega® (Twinlab), Glutamine Fuel Powder® (Twinlab), levoglutamide, L-Glutamine Power (Champion Nutrition), Q.

Background

  • L-glutamine is a nonessential amino acid (i.e., the human body can synthesize it) found mainly in skeletal muscle. Glutamine plays an important role in many functions of the body, including acid-base balance, nitrogen supply, and formation of DNA, protein, and other nutrients. A typical dietary intake is 5-10 grams daily, coming from common dietary animal and plant protein sources. In certain situations, such as in severe illness or trauma, the body may require higher levels of glutamine. Glutamine has been commonly studied in postsurgical, trauma, critically ill, burn, very-low-birthweight, and transplant patients, as well as for reducing side effects of chemotherapy, radiation therapy, and HIV medications. Glutamine is also commonly used to improve general immune system health and for exercise performance enhancement.
  • Some well-designed studies support the use of glutamine as part of parenteral nutrition (nutrition delivered by injection into a vein or muscle) in postsurgical, burn, or ill patients. Further research in patients with malnutrition, digestive concerns, or other illnesses is needed.

Scientific Evidence

Uses

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

A Burns

Evidence suggests that incorporation of glutamine into enteral feeding (tube feeding into the stomach or intestine) and intravenous feeding of burn patients offers benefit.

B Total parenteral nutrition (as adjunct during trauma or after surgery)

Some evidence suggests that incorporation of glutamine into parenteral nutrition (feeding by tube into a vein or muscle) for trauma and postsurgical patients may offer benefit. However, further studies are needed before conclusions can be drawn.

C Critical illness

Although some preliminary evidence suggests that glutamine-enriched feeding may offer benefit to patients with critical illness, not all results from studies agree. Further well-designed research is required before conclusions can be drawn.

C Cystic fibrosis

Currently, there is insufficient evidence to support the use of glutamine for cystic fibrosis. Additional research is needed.

C HIV (medication side effects)

Preliminary evidence suggests a benefit from glutamine in reducing side effects from HIV medications. Further well-designed research is required before conclusions can be drawn.

C Immunomodulation

There is conflicting evidence with regard to glutamine’s effects on the immune system. Further well-designed research is required before conclusions can be drawn.

C Impaired glucose tolerance

Limited evidence suggests that glutamine may be beneficial to patients with impaired glucose tolerance. Further research is required before conclusions can be drawn.

C Inflammatory bowel conditions

Preliminary evidence suggests that glutamine may be beneficial to patients with inflammatory bowel conditions. Further research is required before conclusions can be drawn.

C Malnutrition

There is conflicting evidence with regard to glutamine’s effects on nutrition status. Further research is required before conclusions can be drawn.

C Mood

Early evidence suggests that glutamine may offer slight improvements in mood. Further research is required before conclusions can be drawn.

C Pancreatitis

There is conflicting evidence with regard to glutamine’s effects on pancreatitis. Further well-designed research is required before conclusions can be drawn.

C Pouchitis (Inflammation of a surgically constructed bowel pouch)

Early evidence suggests that glutamine may lessen symptoms of pouchitis. Further research is required before conclusions can be drawn.

C Septicemia (serious bacterial infections in the blood)

There is conflicting evidence with regard to glutamine’s effects on septicemia. Further research is required before conclusions can be drawn.

C Sickle cell anemia

Limited evidence suggests that glutamine may be beneficial to patients with sickle cell anemia. Further research is required before conclusions can be drawn.

C Supplementation in preterm and very low birthweight infants

There is conflicting evidence with regard to the effects of glutamine supplementation in preterm and very-low-birthweight infants. Further research is required before conclusions can be drawn.

C Transplants (stem cell, bone marrow)

There is conflicting evidence with regard to the effects of glutamine supplementation in transplant patients. Further research is required before conclusions can be drawn.

D Diarrhea

Current evidence suggests that glutamine may not be useful in reducing symptoms associated with diarrhea.

D Duchenne muscular dystrophy

Current evidence suggests that glutamine may not be beneficial to patients with Duchenne muscular dystrophy.

D Exercise performance enhancement

Current evidence does not support the use of glutamine for weight training or endurance exercise.

D Malabsorption syndrome

Current evidence suggests that glutamine may not offer benefits to patients with malabsorption syndrome (short bowel syndrome).

D Reducing side effects of chemotherapy or radiotherapy

The majority of evidence does not support the use of glutamine for reduction of side effects associated with chemotherapy or radiotherapy.

*Key to grades:

Tradition

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

  • Acidosis, aging, alcohol intoxication, antioxidant, anxiety, arthritis, attention-deficit hyperactivity disorder (ADHD), autism, brain injuries, cachexia (muscle wasting), cancer, cholecystitis (laparoscopic surgery), cholera, chronic fatigue syndrome, cognitive function, concentration enhancement, Crohn’s disease, depression, diabetes, elimination of blood toxins, energy, esophageal cancer, exercise recovery, fatigue, fetal development, growth, growth hormone stimulation, hematopoiesis, HIV/AIDS, inflammation, ischemia-reperfusion injury prevention, kidney disease, memory, mouth sores, muscle soreness, muscle wasting, nutritional deficiencies, peripheral neuropathy, pneumonia, psychiatric disorders, seizures, sore throat, spinal cord injury, stress, surgery (ileoanal pouch), trauma, ulcerative colitis, ulcers, weight gain, wound healing.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

  • Generally, it is not suggested to take glutamine in the dry powdered form. The powder should be mixed in eight ounces of water, mixed well, and totally consumed by rinsing out the glass and drinking again.
  • For burns, 4.3 grams of glutamine has been taken by tube to the stomach or intestine every four hours until healing is complete. One half (0.5) gram of glutamine granules per kilogram of body weight has been taken by mouth or by tube to the stomach or intestine daily for up to 14 days. Up to 0.5 grams per kilogram of body weight daily as glutamine dipeptide has been taken by mouth until postburn day 12. Continuous infusion of intravenous glutamine (0.57 grams per kilogram of body weight daily) has been used for at least 30 days
  • For critical illness, 30.5 grams of glutamine per liter enteral (tube-administered) feed has been taken by mouth for a minimum of seven days. Also, 30.5 grams of glutamine per 100 grams of protein in an enteral feed has been taken by mouth for a minimum of five days. Five grams of glutamine per bottle of tube-administered feed has been taken by mouth via a nasogastric tube for 18 hours daily with a six-hour feed-free period. Twenty to forty grams of glutamine has been taken by mouth daily through a tube to the stomach or intestine. A tube-administered feed with 0.6 grams of glutamine per kilogram of body weight has been used. The duration of glutamine was generally dependent on the duration of tube feeding required. Total parenteral nutrition (nutrition administered through a tube to the stomach or intestine; TPN) containing glutamine (25 grams per 1,000 milliliters of solution, the amount of solution used was not clear) has been used.
  • For cystic fibrosis, 0.7 grams of glutamine per kilogram of body weight has been taken by mouth daily for four weeks.
  • For exercise performance enhancement, 0.9 grams of glutamine per kilogram of body weight has been taken by mouth for six weeks. A single dose of 0.03 grams of glutamine per kilogram of body weight has been taken by mouth.
  • For HIV medication side effects, 10 grams of glutamine has been taken by mouth three times daily for 10 days.
  • For immunomodulation (changing the immune system), 0.1 grams of glutamine per kilogram of body weight has been taken by mouth four times daily for 14 days. After 60 minutes of exercise, 3.5 grams of glutamine in 0.5 liters of aqueous solution has been taken by mouth four times at intervals of 45 minutes. Also, 100 milligrams of glutamine per kilogram of body weight dissolved in lemonade 30 minutes has been taken by mouth before the end of exercise, at the end of exercise, and 30 minutes after the end of exercise for each of three exercise bouts. In trauma patients, 30.5 grams of glutamine per 100 grams of tube-administered protein was provided for a minimum of five days. In athletes, either 2.5 or 5 grams has been taken by mouth each time immediately following exercise and two hours later. Continuous infusion of 0.5 grams of glutamine dipeptide per kilogram of body weight for 72 hours, starting 24 hours prior to surgery, has been used. Glutamine (0.18 grams per kilogram of body weight) has been administered by tube from postoperative days 1 to 6. Glutamine (up to 0.57 grams per kilogram of body weight) for up to 21 days, or 21 grams of glutamine added daily as Dipeptiven®, has been administered by tube for one day before an operation to three days after.
  • For impaired glucose tolerance, 0.4 grams of alanyl-glutamine per kilogram of body weight as Dipeptiven® has been injected or infused from 24 hours after trauma and continued for seven days.
  • For malabsorption syndrome (short bowel syndrome), 30 grams of glutamine daily has been taken by mouth for up to four weeks.
  • For mood, nutrition containing 40 grams of glutamine has been administered by tube daily until the patient was eating 50% of estimated requirements.
  • For pancreatitis (inflamed pancreas), nutrition with an added 0.3 grams of Dipeptiven® per kilogram of body weight has been administered by tube for a minimum of one week.
  • For pouchitis (inflammation of a surgically constructed bowel pouch), rectal suppositories containing one gram of glutamine have been used twice daily for 21 days.
  • For reducing side effects of chemotherapy or radiotherapy, up to 30 grams of glutamine (up to three divided doses) or 2 grams per square meter of body surface area (as glutamine or dipeptidyl glutamine) has been taken by mouth daily up to five days prior to chemotherapy use, during chemotherapy use, and for up to an additional 14 days, or for up to 14 days following radiotherapy. Oral rinse with up to two grams of glutamine in 30 milliliters of saline four times daily, or four grams of swish-and-swallow twice daily for up to 28 days or for four days past the resolution of inflamed mouth has been used for reduction of inflamed mouth. Fourteen to 26 grams of glutamine has been administered daily by tube solution. The duration was from one day prior to chemotherapy and during chemotherapy (five days) in one study and until desired neutrophil count (greater than 0.5 x 109/L) in the second.
  • For septicemia (blood poisoning), 0.1 grams of glutamine per kilogram of body weight has been injected daily over a 12-hour period, with no evidence of benefit.
  • For sickle cell anemia, 30 grams of glutamine daily has been taken by mouth for four weeks.
  • As an adjunct during trauma or after surgery, up to 0.5 grams of glutamine-enriched TPN per kilogram of body weight (as single amino acid or as alanyl-glutamine such as Dipeptiven®, or as glycyl-glutamine) has been administered by tube daily for up to 10 days. Thirty grams as Dipeptiven® has been administered by tube daily for 14 days. Twenty grams of glutamine has been used for three days after surgery or for the duration of the hospital stay.
  • For transplants (stem cell, bone marrow), 1.0 grams of glutamine per square meter of body surface area, swished and swallowed, has been used from admission until day 28. Two grams of glutamine per square meter of body surface area (maximal dose of four grams daily) has been taken by mouth. Total parenteral nutrition (TPN) containing glutamine (0.57 grams per kilogram of body weight as dipeptide) has been administered by tube for up to an average of 26 days. A 50-gram daily infusion of glycyl-glutamine has been used from the start of conditioning until discharge. Glutamine (2,380 milligrams per 100 milliliters of TPN solution) has been given by tube for approximately 30 days.

Children (under 18 years old)

  • For critical illness, daily enteral administration of 0.3 grams of glutamine per kilogram of body weight was used over five days.
  • For Crohn’s disease, a tube feeding with 42% amino acids as glutamine has been used for four weeks.
  • For diarrhea, 0.3 grams of glutamine per kilogram of body weight has been taken by mouth daily for seven days.
  • For Duchenne muscular dystrophy, up to 0.6 grams per kilogram of body weight has been injected daily for up to six months.
  • For malnutrition, formula supplemented with 16.2 grams of glutamine has been taken by mouth for 10 days.
  • For sickle cell anemia, 600 milligrams of glutamine per kilogram of body weight has been injected for 24 weeks.
  • For supplementation in preterm and very-low-birthweight infants, up to 0.6 grams of glutamine per kilogram of body weight has been used daily until day 30 of life.
  • For total parenteral nutrition (as an adjunct during trauma or after surgery), 0.4 grams of glutamine per kilogram of body weight has been given by tube daily from day 2 following surgery to until day 31 at the latest.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

  • Avoid with known allergy or hypersensitivity to glutamine or any component of the formulation.

Side Effects and Warnings

  • Use cautiously in trauma patients due to reports of deaths due to sepsis (harmful bacteria and their toxins in tissues) or multiorgan failure with use.
  • Use cautiously in autologous (cell or tissue) transplant patients due to reports of worsened mouth inflammation, increased painkiller use, and extended hospital stay.
  • Use cautiously in patients with diseased, severely scarred livers (cirrhosis) without transjugular intrahepatic portosystemic shunts (artificial channels leading from the portal vein to a vein in the liver), due to reports of increased ammonia in the blood, as well as increased reaction time.
  • Use cautiously in patients with liver disorders, as liver dysfunction has been reported.
  • Use cautiously in patients with psychiatric concerns, due to reports of increased manic symptoms.
  • Use cautiously in patients with kidney problems.
  • Glutamine may increase blood insulin levels, which may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those using drugs, herbs, or supplements that affect blood sugar, especially insulin. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
  • Glutamine may also cause constipation, bloating, and other unspecified gastrointestinal side effects.
  • Glutamine is not recommended in pregnant or breastfeeding women, due to a lack of available scientific evidence.
  • Avoid with known allergy or hypersensitivity to glutamine or any component of the formulation.

Pregnancy and Breastfeeding

  • Glutamine is not suggested in pregnant or breastfeeding women due to a lack of available scientific evidence.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

  • Glutamine may increase blood insulin levels, which may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar, especially insulin. Patients taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
  • Glutamine may also interact with agents for muscle wasting, agents that reduce chemotherapy side effects, anesthetics, antibiotics, antidepressants, antidiarrheals, anti-inflammatory agents, antipsychotics, antiretroviral agents, celecoxib, growth hormones, immunosuppressants, indomethacin, insulin-like growth factor 1 (IGF-1), interferon-alpha, loperamide, methotrexate, nonsteroidal anti-inflammatory agents (NSAIDs), opiates, protein-sparing drugs, somatostatin, sulpiride, and valproic acid.

Interactions with Herbs and Dietary Supplements

  • Glutamine may increase blood insulin levels, which may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar or raise insulin levels. Blood glucose levels may require monitoring, and doses may need adjustment.
  • Glutamine may also interact with antibacterials, antidepressants, antidiarrheals, anti-inflammatory herbs and supplements, antioxidants and antioxidant-containing foods, antipsychotics, antiretroviral herbs and supplements, arginine, beta-hydroxy-beta-methylbutyrate (BHMB), branched-chain amino acids, carbohydrates, chemotherapeutic herbs and supplements, exercise performance herbs and supplements, fiber, fish, fructose, growth hormones, herbs and supplements for muscle wasting, immunostimulants, immunosuppressants, monosodium glutamate (MSG), narcotics, omega-3 fatty acids, ornithine alpha-ketoglutarate (OKG), probiotics and probiotic-containing foods, protein, protein-sparing herbs and supplements, weight-promoting herbs, supplements, and diets, and wound-healing herbs and supplements.

Author Information

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  1. Berard MP, Zazzo JF, Condat P, et al. Total parenteral nutrition enriched with arginine and glutamate generates glutamine and limits protein catabolism in surgical patients hospitalized in intensive care units. Crit Care Med 2000;28(11):3637-3644. View Abstract
  2. Blijlevens NM, Donnelly JP, Naber AH, et al. A randomised, double-blinded, placebo-controlled, pilot study of parenteral glutamine for allogeneic stem cell transplant patients. Support Care Cancer 2005;13(10):790-796. View Abstract
  3. Byrne TA, Wilmore DW, Iyer K,et al. Growth hormone, glutamine, and an optimal diet reduces parenteral nutrition in patients with short bowel syndrome: a prospective, randomized, placebo-controlled, double-blind clinical trial. Ann Surg 2005;242(5):655-661. View Abstract
  4. Escolar DM, Buyse G, Henricson E, et al. CINRG randomized controlled trial of creatine and glutamine in Duchenne muscular dystrophy. Ann Neurol 2005;58(1):151-155. View Abstract
  5. Garre D, Patenaude J, Nedelec B, et al. Decreased mortality and infectious morbidity in adult burn patients given enteral glutamine supplements: a prospective, controlled, randomized clinical trial. Crit Care Med 2003;31(10):2444-2449. View Abstract
  6. Giris M, Erbil Y, Dogru-Abbasoglu S,et al. The effect of heme oxygenase-1 induction by glutamine on TNBS-induced colitis. The effect of glutamine on TNBS colitis. Int J Colorectal Dis 2007;22(6):591-599. View Abstract
  7. Goeters C, Wenn A, Mertes N, et al. Parenteral L-alanyl-L-glutamine improves 6-month outcome in critically ill patients. Crit Care Med 2002;30(9):2032-2037. View Abstract
  8. Kalhan SC, Parimi PS, Gruca LL, et al. Glutamine supplement with parenteral nutrition decreases whole body proteolysis in low birth weight infants. J Pediatr 2005;146(5):642-647. View Abstract
  9. Lima AA, Brito LF, Ribeiro HB, et al. Intestinal barrier function and weight gain in malnourished children taking glutamine supplemented enteral formula. J Pediatr Gastroenterol Nutr 2005;40(1):28-35. View Abstract
  10. Marcora S, Lemmey A, Maddison P. Dietary treatment of rheumatoid cachexia with beta-hydroxy-beta-methylbutyrate, glutamine and arginine: a randomised controlled trial. Clin Nutr 2005;24(3):442-454. View Abstract
  11. Marwood S, Bowtell J. No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise. J Sports Sci 2008;26(10):1081-90. View Abstract
  12. Thompson SW, McClure BG, Tubman TR. A randomized, controlled trial of parenteral glutamine in ill, very low birth-weight neonates. J Pediatr Gastroenterol Nutr 2003;37(5):550-553. View Abstract
  13. van den Berg A, van Elburg RM, Westerbeek EA,et al. Glutamine-enriched enteral nutrition in very-low-birth-weight infants and effects on feeding tolerance and infectious morbidity: a randomized controlled trial. Am J Clin Nutr 2005;81(6):1397-1404. View Abstract
  14. Yalcin SS, Yurdakok K, Tezcan I,et al. Effect of glutamine supplementation on diarrhea, interleukin-8 and secretory immunoglobulin A in children with acute diarrhea. J Pediatr Gastroenterol Nutr 2004;38(5):494-501. View Abstract
  15. Zhou YP, Jiang ZM, Sun YH, et al. The effect of supplemental enteral glutamine on plasma levels, gut function, and outcome in severe burns: a randomized, double-blind, controlled clinical trial. JPEN J.Parenter.Enteral Nutr. 2003;27(4):241-245. View Abstract

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.