The Health Benefits of L-Glutamine

May improve gut health and wound healing

Female runner in park
Matthew Leete/Photodisc/Getty Images

L-glutamine is the most plentiful amino acid in the body. It's involved in protein synthesis and serves as fuel for the immune system. Most people benefit from taking glutamine when their immune system is weakened or for healing a major wound like a burn or after surgery.

Though l-glutamine is found in food and supplements, it's unnecessary to take supplemental l-glutamine because it's a non-essential amino acid. That means that your body can make it on its own.

Glutamine also used to be a major mainstay for bodybuilders and athletes for building muscle and reducing recovery times. But taking this supplement has since been abandoned because there's no solid research backing this up today. Here is what you need to know about l-glutamine.

Health Benefits

Years ago glutamine was almost considered a conditionally essential amino acid only for those who are critically ill or injured, such as in the case for burn victims or someone who was physically stressed and at risk of muscle and tissue breakdown. In these situations, supplementing with glutamine could help reduce healing time and would be of benefit.

L-glutamine is also occasionally used to alleviate some of the side effects of chemotherapy. It also has been used for decades for health and exercise purposes in dietary supplements, though many of these claims are unsubstantiated or exaggerated. Here are some potential benefits of l-glutamine.

Immune System Support

Glutamine is important for the immune system as it helps it to function optimally. People who are critically ill or who have experienced severe physical trauma have low glutamine levels due to either a reduction in skeletal glutamine production or cells using up the body's stored glutamine more rapidly due to the trauma.

For that reason, supplementing with l-glutamine could help improve immune system function and speed recovery. Specifically for burn patients, supplementing with glutamine can help maintain healthy immune function, improve wound healing, and shorten hospital stay. In fact, an older study a 2009 study from India reported that the enteral delivery of L-glutamine reduced bacterial complications as well as hospital stays by almost 17 days compared to a control group.

For healthy individuals, the benefits of glutamine for immune function just aren't there. In that sense, if you're not immunocompromised, critically ill, or recovering from surgery, taking a daily glutamine supplement to improve your health is largely a waste of money.

Muscle Building, Fat Loss, and Recovery

Much to the bodybuilding community's dismay, l-glutamine does not offer the muscle-building and fat loss benefits it was once believed to provide. Though scientists continue to look into these claims, the existing research doesn't support them.

For instance, one study examined the effects of glutamine supplementation combined with resistance training in young adults, ages 18 to 24, and found that there were no significant differences between the group who took glutamine and the placebo group. Both groups experienced similar muscle and strength gains.

When it comes to weight loss, several studies support the claim.

This six-week study observed sixty-six patients with type 2 diabetes, They were split into two groups and instructed to take either 30 grams per day of glutamine, or they received a placebo. The group that received glutamine experienced improved cardiovascular risk factors and body composition.

And this study demonstrated that taking glutamine for 4 weeks results in reductions in body weight and waist circumference.

On the other hand, several studies have found the opposite to be true, that glutamine supplementation has no effect on weight loss and body composition. Research is ongoing to determine whether L-glutamine supplementation has positive effects for building muscle and losing weight.

All is not lost for people hoping to reap some sort of athletic benefits from L-glutamine supplementation. Several studies have shown that supplementing with L-glutamine once per day can reduce muscle recovery time and soreness after a tough workout.

In a sense, L-glutamine may help with athletic performance by delaying fatigue. If you're not fatigued, you're able to perform better in the gym and on the field.

Chemotherapy Side Effects

Glutamine may play a pivotal role in improving the quality of life for cancer patients undergoing chemotherapy. In fact, symptoms associated with chemotherapy may be less severe with a lower dose and after treatment.

Chemotherapy often breaks down tissue in the intestinal lining causing mouth and throat sores, called mucositis. Some studies report a reduction in painful mucosal symptoms and ulceration associated with radiation and chemotherapy treatment.

Conversely, other studies have found marginal effects of oral L-glutamine supplementation on mucositis.Though it may have the potential to reduce the degree of pain and discomfort, further research is needed.

Possible Side Effects

L-glutamine is safe for human consumption and does not generally cause significant side effects even at doses up to 40 grams per day. More than that and you may experience mild symptoms such as bloating, gas, nausea, dizziness, heartburn, or stomach upset.

With that said, there have been few studies investigating the long-term effects of l-glutamine supplements or at which doses l-glutamine may cause toxicity. There is evidence, albeit slight, that l-glutamine supplements may trigger seizures in people on anti-convulsant medications. Because l-glutamine is metabolized by the liver, it may need to be avoided in people with severe liver disease.

Due to the lack of research, it is best to avoid l-glutamine during pregnancy or while breastfeeding. While l-glutamine has been used safely in infants and children, it should only be prescribed under the supervision of a pediatrician.

Dosage and Preparation

Your l-glutamine requirements are generally fulfilled through the foods you eat each day. However, if you plan to use a supplement form of l-glutamine, 3 to 6 grams per day is considered safe.

According to an older report in Regulatory Toxicology and Pharmacology, 14 grams of supplemental l-glutamine is safe for healthy adults and no more than 0.7 grams per day per kilogram of body weight in children.

L-glutamine supplements are available in powder, oral capsule, and oral tablet form. Generally, it can be found at your local health food stores, pharmacies, grocery stores, and online.

What to Look For

Because supplement manufacturers in the United States aren't required to put their products through rigorous testing and verification processes, it can be difficult to know whether the product you're purchasing is what it says it is. For that reason, look for brands that voluntarily submit their products for inspection by an independent certifying body like the U.S. Pharmacopeia (USP), ConsumerLab, or NSF International.

Choosing products that display the certifications mentioned above can help ensure you're getting the highest quality and safety standards. If you are vegan or vegetarian, look for l-glutamine supplements made from fermented plant-based materials (usually beets).

Foods Higher in L-Glutamine

To get more l-glutamine in your diet, look for these foods the next time you go to the grocery store:

  • Beef: 1.2 grams per 4-ounce serving
  • Eggs: 0.6 grams per two eggs
  • Tofu: 0.6 grams per 3.5-ounce serving
  • Corn: 0.4 grams per half-cup serving
  • Milk: 0.3 grams per half-cup serving
  • White rice: 0.3 grams per half-cup serving


Frequently Asked Questions

  • Can I get enough l-glutamine from food?

    Yes, you can get plenty of l-glutamine from your diet. Because l-glutamine is an amino acid, choosing high protein foods will help ensure you're getting more than your fair share.

  • When should I take l-glutamine?

    You can take l-glutamine any time of the day. If using it to improve workouts and reduce the onset of fatigue, try using it 30 minutes prior to your workout, during your workout, and/or immediately following a strenuous workout.

  • How much l-glutamine should I take for leaky gut?

    Glutamine is involved in the health of the intestinal lining. L-glutamine deficiency is highly unlikely however reduced glutamine due to chronic illness or trauma is possible and could result in diarrhea or "leaky gut." For that reason, supplementing with l-glutamine may be helpful.


    Dissolve 10 to 15 grams of l-glutamine powder in water; take 1 hour before a meal in the morning and evening daily.

  • How do I take L-glutamine for sugar cravings?

    The idea is that L-glutamine is an amino acid, amino acids are building blocks for protein, and protein helps keep you full and satisfied. So if you take L-glutamine you'll be fuller for longer and have fewer sugar cravings. Unfortunately, there isn't any research supporting that L-glutamine will help with sugar cravings.

  • Does l-glutamine help with alcohol cravings?

    Glutamine production is disturbed when someone drinks alcohol. Once alcohol is out of the system, the body begins producing glutamine again. For alcoholics, discontinuing the use of alcohol leads to alcohol withdrawals of which cause significant undesirable symptoms. It's believed that supplementing with L-glutamine can help reduce symptoms of alcohol withdrawals, however, more research is needed.

  • What is the difference between l-glutamine and glutamine?

    There is little difference between l-glutamine and glutamine and the two terms are often used interchangeably. Glutamine is an amino acid and l-glutamine is an isomer of glutamine with a slightly different chemical structure. L-glutamine is the type found in food, supplements, and the human body.

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27 Sources
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  1. Cruzat V, Macedo Rogero M, Noel Keane K, Curi R, Newsholme P. Glutamine: Metabolism and Immune Function, Supplementation and Clinical TranslationNutrients. 2018;10(11):1564. Published 2018 Oct 23. doi:10.3390/nu10111564

  2. Kerksick CM, Wilborn CD, Roberts MD, et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15(1):38. Published 2018 Aug 1. doi:10.1186/s12970-018-0242-y

  3. Lacey JM, Wilmore DW. Is glutamine a conditionally essential amino acid? Nutr Rev. 1990 Aug;48(8):297-309. doi: 10.1111/j.1753-4887.1990.tb02967.x

  4. Peng X, Wang SL. Glutamine and immunonutrition for burn patients. Zhonghua Shao Shang Za Zhi. 2009;25(5):321-4.

  5. Gaurav K, Goel RK, Shukla M, Pandey M. Glutamine: A novel approach to chemotherapy-induced toxicity. Indian J Med Paediatr Oncol. 2012;33(1):13-20. doi:10.4103/0971-5851.96962

  6. Candow DG, Chilibeck PD, Burke DG, Davison KS, Smith-Palmer T. Effect of glutamine supplementation combined with resistance training in young adults. Eur J Appl Physiol. 2001 Dec;86(2):142-9. doi:10.1007/s00421-001-0523-y

  7. Mansour A, Mohajeri-Tehrani MR, Qorbani M, Heshmat R, Larijani B, Hosseini S. Effect of glutamine supplementation on cardiovascular risk factors in patients with type 2 diabetes. Nutrition. 2015 Jan;31(1):119-26. doi: 10.1016/j.nut.2014.05.014

  8. Laviano A, Molfino A, Lacaria MT, Canelli A, De Leo S, Preziosa I, Rossi Fanelli F. Glutamine supplementation favors weight loss in nondieting obese female patients. A pilot study. Eur J Clin Nutr. 2014 Nov;68(11):1264-6. doi:10.1038/ejcn.2014.184

  9. Candow DG, Chilibeck PD, Burke DG, Davison KS, Smith-Palmer T. Effect of glutamine supplementation combined with resistance training in young adults. Eur J Appl Physiol. 2001 Dec;86(2):142-9. doi:10.1007/s00421-001-0523-y.

  10. Rahmani Nia F, Farzaneh E, Damirchi A, Shamsi Majlan A. Effect of L-glutamine supplementation on electromyographic activity of the quadriceps muscle injured by eccentric exerciseIran J Basic Med Sci. 2013;16(6):808-812. PMID:23997909

  11. Córdova-Martínez A, Caballero-García A, Bello HJ, Pérez-Valdecantos D, Roche E. Effect of Glutamine Supplementation on Muscular Damage Biomarkers in Professional Basketball PlayersNutrients. 2021;13(6):2073. Published 2021 Jun 17. doi:10.3390/nu13062073

  12. Legault Z, Bagnall N, Kimmerly DS. Influence of Oral L-Glutamine Supplementation on Muscle Strength Recovery and Soreness Following Unilateral Knee Extension Eccentric Exercise. Int J Sport Nutr Exerc Metab. 2015 Oct;25(5):417-26. doi:10.1123/ijsnem.2014-0209

  13. Coqueiro AY, Rogero MM, Tirapegui J. Glutamine as an Anti-Fatigue Amino Acid in Sports NutritionNutrients. 2019;11(4):863. Published 2019 Apr 17. doi:10.3390/nu11040863

  14. Peng TR, Lin HH, Yang LJ, Wu TW. Effectiveness of glutamine in the management of oral mucositis in cancer patients: a meta-analysis of randomized controlled trials. Support Care Cancer. 2021 Aug;29(8):4885-4892. doi:10.1007/s00520-021-06060-9

  15. Anderson PM, Lalla RV. Glutamine for Amelioration of Radiation and Chemotherapy Associated Mucositis during Cancer Therapy. Nutrients. 2020 Jun 4;12(6):1675. doi:10.3390/nu12061675

  16. Widjaja NA, Pratama A, Prihaningtyas R, Irawan R, Ugrasena I. Efficacy Oral Glutamine to Prevent Oral Mucositis and Reduce Hospital Costs During Chemotherapy in Children with Acute Lymphoblastic LeukemiaAsian Pac J Cancer Prev. 2020;21(7):2117-2121. Published 2020 Jul 1. doi:10.31557/APJCP.2020.21.7.2117

  17. Shuai T, Tian X, Xu LL, et al. Oral Glutamine May Have No Clinical Benefits to Prevent Radiation-Induced Oral Mucositis in Adult Patients With Head and Neck Cancer: A Meta-Analysis of Randomized Controlled TrialsFront Nutr. 2020;7:49. Published 2020 Apr 17. doi:10.3389/fnut.2020.00049

  18. Garlick PJ. Assessment of the safety of glutamine and other amino acids. J Nutr. 2001 Sep;131(9 Suppl):2556S-61S. doi:10.1093/jn/131.9.2556S

  19. Holecek M. Side effects of long-term glutamine supplementation. JPEN J Parenter Enteral Nutr. 2013;37(5):607-16. doi:10.1177/0148607112460682

  20. Dhaher R, Chen EC, Perez E, Rapuano A, Sandhu MRS, Gruenbaum SE, Deshpande K, Dai F, Zaveri HP, Eid T. Oral glutamine supplementation increases seizure severity in a rodent model of mesial temporal lobe epilepsy. Nutr Neurosci. 2022 Jan;25(1):64-69. doi:10.1080/1028415X.2019.1708568

  21. Barker-haliski M, White HS. Glutamatergic Mechanisms Associated with Seizures and Epilepsy. Cold Spring Harb Perspect Med. 2015;5(8):a022863. doi:10.1101/cshperspect.a022863

  22. Lenders CM, Liu S, Wilmore DW, et al. Evaluation of a novel food composition database that includes glutamine and other amino acids derived from gene sequencing data. Eur J Clin Nutr. 2009;63(12):1433-9. doi:10.1038/ejcn.2009.110

  23. Andrew Shao, John N. Hathcock. Risk assessment for the amino acids taurine, l-glutamine and l-arginine. Regulatory Toxicology and Pharmacology. 2008; 50:3 376-399. doi:10.1016/j.yrtph.2008.01.004

  24. Achamrah N, Déchelotte P, Coëffier M. Glutamine and the regulation of intestinal permeability: from bench to bedside. Curr Opin Clin Nutr Metab Care. 2017 Jan;20(1):86-91. doi:10.1097/MCO.0000000000000339

  25. Prisciandaro JJ, Schacht JP, Prescot AP, Renshaw PF, Brown TR, Anton RF. Brain Glutamate, GABA, and Glutamine Levels and Associations with Recent Drinking in Treatment-Naïve Individuals with Alcohol Use Disorder Versus Light Drinkers. Alcohol Clin Exp Res. 2019 Feb;43(2):221-226. doi:10.1111/acer.13931

  26. Butts M, Singh Paulraj R, Haynes J, Arthur S, Singh S, Sundaram U. Moderate Alcohol Consumption Inhibits Sodium-Dependent Glutamine Co-Transport in Rat Intestinal Epithelial Cells in Vitro and Ex Vivo. Nutrients. 2019 Oct 18;11(10):2516. doi:10.3390/nu11102516

  27. Thoma R, Mullins P, Ruhl D, et al. Perturbation of the glutamate-glutamine system in alcohol dependence and remission [published correction appears in Neuropsychopharmacology. 2012 Apr;37(5):1321]. Neuropsychopharmacology. 2011;36(7):1359-1365. doi:10.1038/npp.2011.20

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