L-Glutamine Uses and Health Benefits

Show Article Table of Contents

Female runner in park
Matthew Leete/Photodisc/Getty Images

L-glutamine is an amino acid found in the body, primarily in skeletal muscle. It is also available in a number of common foods and in dietary supplement form. L-glutamine supplements are said to increase muscle mass, as well as treat certain health conditions.

L-glutamine has many functions in the body, including protein synthesis. It is also essential to the proper function of the immune system. In addition, L-glutamine appears to play a role in brain function and digestion. 


L-glutamine supplements are purported to enhance exercise performance, as well as help with the following health conditions: anxietyCrohn's diseasedepressioninsomnia, and ulcerative colitis.

Additionally, L-glutamine is used to protect against the adverse effects of certain medical treatments, such as chemotherapy. Glutamine (administered by mouth or intravenously) is also said to help promote healing and reduce the risk of complications in critically ill people who have had traumatic injuries or burns or who have undergone surgery.

Health Benefits

Although research on the health effects of taking L-glutamine supplements is limited and often dated, some studies suggest that L-glutamine supplements may offer certain health benefits. Here's a look at several key study findings:

1) Athletic Performance

There's little scientific evidence to support the claim that L-glutamine supplements are beneficial to athletes, according to a 2008 report published in the Journal of Nutrition. The report's authors note that, while many athletes take L-glutamine supplements to protect against exercise-related impairment of the immune system, L-glutamine supplementation does not appear to prevent post-exercise changes in immune function.

To date, few clinical trials have looked at the effects of L-glutamine supplements on sports performance. However, a small study published in the Journal of Sports Medicine and Physical Fitness in 1998 found that L-glutamine failed to enhance high-intensity exercise performance in a group of 10 male athletes.

2) Cancer Treatment Side Effects

Some studies indicate that L-glutamine may be beneficial to people undergoing cancer treatment. For a report published in Alternative Medicine Review in 1999, for instance, scientists looked at the available data on the supplemental use of L-glutamine may help offset the muscle glutamine depletion that often occurs in cancer patients. In addition, the report's authors note that L-glutamine may help minimize the side effects of chemotherapy and radiation therapy. However, the authors also caution that L-glutamine may stimulate the growth of some tumors.

In a more recent study (published in the journal Colorectal Disease in 2007), researchers found that L-glutamine supplementation decreased post-operative complications and reduced the duration of hospital stay among patients undergoing colorectal surgery for cancer. The study involved 109 patients with colorectal cancer.

An oral gargle with glutamine may help reduce the severity and duration of chemotherapy-induced mucositis.

Food Sources

Glutamine is found in many common plant and animal foods, including:

  • Barley
  • Beef
  • Cabbage
  • Corn
  • Cottage cheese
  • Egg whites
  • Milk
  • Peanuts
  • Pork
  • Poultry
  • Raw parsley
  • Raw spinach
  • Soy
  • Yogurt

Side Effects

There's some concern that using L-glutamine supplements in combination with certain medications (including chemotherapy drugs and anti-seizure medications) may produce harmful effects.

Additionally, taking L-glutamine may be harmful to people with certain health conditions, such as liver disease (cirrhosis, hepatic encephalopathy), mania, and seizure disorders.

Supplements haven't been tested for safety and keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established. If you're considering using L-glutamine, talk with your primary care provider first. 

Where to Find Them

Available for purchase online, L-glutamine supplements are sold in many natural-food stores and in stores specializing in dietary supplements.

Was this page helpful?
Article Sources
  • Gleeson M. "Dosing and efficacy of glutamine supplementation in human exercise and sport training." J Nutr. 2008 Oct;138(10):2045S-2049S.
  • Haub MD, Potteiger JA, Nau KL, Webster MJ, Zebas CJ. "Acute L-glutamine ingestion does not improve maximal effort exercise." J Sports Med Phys Fitness. 1998 Sep;38(3):240-4.
  • Miller AL. "Therapeutic considerations of L-glutamine: a review of the literature." Altern Med Rev. 1999 Aug;4(4):239-48.
  • Oguz M, Kerem M, Bedirli A, Mentes BB, Sakrak O, Salman B, Bostanci H. "L-alanin-L-glutamine supplementation improves the outcome after colorectal surgery for cancer." Colorectal Dis. 2007 Jul;9(6):515-20.
  • Tsujimoto T, Yamamoto Y, Wasa M, Takenaka Y, Nakahara S, Takagi T, Tsugane M, Hayashi N, Maeda K1, Inohara H, Uejima E, Ito T. L-glutamine decreases the severity of mucositis induced by chemoradiotherapy in patients with locally advanced head and neck cancer: a double-blind, randomized, placebo-controlled trial. Oncol Rep. 2015 Jan;33(1):33-9. doi: 10.3892/or.2014.3564. Epub 2014 Oct 23.