Feb 15, 2019

Glutamine particularly L-Glutamine supplementation in a powder form is widely used by strength and endurance athletes, especially for its muscle tissue preservative nature. A person looking for weight loss, build muscles and burn extra fat can also use L-Glutamine supplementation along with the natural food.

 But before sheepishly using it we should understand why L-Glutamine. Let us understand it step by step.


Glutamine is one of the 20 naturally occurring amino acids present in the dietary protein. In fact, L-glutamine is the most abundant amino acid found in the bloodstream and approximately 30–35% of it is nitrogenous amino acid. Current researches have proved that it is conditionally an essential amino acid (Lacey JM and Wilmore DW, 1990) because in natural conditions body can supply an adequate amount through natural pathways, but in case of stress caused by excessive exercise or critical illness glutamine supplementation is essential (Ziegler TR, 2001).


Based on its optical structure glutamine is divided into 2 forms.

 D-glutamine is mostly found in bacteria fermented products like yoghurt and cheese. The quantity found in food is thought to be harmless to humans. Though D-glutamine present in food and supplements has no nutritional value but it produces enkephalins, the natural pain reliever in the body. This has not yet been established by any scientific research.

 On the other hand, L-Glutamine is the most common and beneficial form of glutamine. Approximately 70% of our body’s internal glutamine is produced in skeletal muscles from where it travels to the small intestine, kidney and WBCs. These are the main sites of glutamine usage.

 L-Glutamine is also subdivided into 2 groups, regular L-Glutamine and Trans-Alanyl-Glutamine (TAG). Regular L-Glutamine is the free form, its absorption rate is higher and has to be taken along with food. But TAG is amino acid attached to another amino acid, it takes longer time to digest and can be taken on an empty stomach.


 L-Glutamine is involved in protein - regulation, synthesis and breakdown. It significantly affects BCAAs metabolism, gut barrier maintenance, proper immune response, glucose formation, water transport, neurotransmission, etc.

Kidneys are the primary utiliser of glutamine where ammonia cleaved from glutamine helps to maintain acid-base balance of the body.


 New researches show L-Glutamine benefits the body in the following ways:

  • Improves Gastrointestinal Health: L-glutamine benefits in digestive issues such as Irritable Bowel Syndrome (IBS), Crohn’s Disease, Ulcerative Colitis, Diverticulosis, Diverticulitis, Leaky Gut or any of the issues associated with leaky gut (like joint pain, rosacea or any type of autoimmune response). Because it is an important nutrient for the intestines to rebuild and repair, thus we need this amino acid in our diet on a regular basis (R.R.W.J. van der Hulst et al. 1993). A study published in the Journal of Clinical Immunology found that L-Glutamine normalises the effects of the TH2 immune response that stimulates inflammatory cytokines. These studies show that L-glutamine reduces intestinal inflammation and helps people recover from food sensitivities.
  • Helps Leaky Gut and Ulcers: Leaky Gut Syndrome is one of the most common problems in the current society. It can cause autoimmune diseases, thyroid issues such as Hashimoto’s disease, arthritis and skin issues like psoriasis, etc. Glutamine is the major fuel source for cells of the small intestine. A study published in the medical journal, Lancet, found that supplementing with L-glutamine leads to a decrease of intestinal permeability (R.R.W.J. van der Hulst et al. 1993) thus helps heal Leaky Gut. It also heals ulcers by protecting from further damage, along with this it offers a healthier natural alternative to antibiotics for the treatment of stomach ulcers (Bonnie Prescott,  2009).
  • Boosts Brain Health - L-Glutamine is the precursor of glutamate, which acts as a neurotransmitter. If glutamine-glutamate cycle gets disturbed it can result in all kinds of brain problems, including Reye’s Syndrome, Epilepsy, Bipolar Disorder, Schizophrenia, Anxiety, Depression and Alcohol Addiction (Albrecht J, 2010). A study conducted by Soomro I, 2018 at the New York University School of Medicine showed that even mild traumatic brain injury causes brain atrophy, and most of this damage was because of the disrupted glutamine-glutamate cycle and an abnormal increase in glutamate levels. 
  • Promotes Muscle Growth and Decreases Muscle Wasting - During an intense workout, body under goes stress condition then muscles and tendons require more glutamine than the amount supplied by a normal regular diet. It is proved by clinical researches that after an intense workout, the levels of cellular glutamine can drop even by 50% and plasma levels by 30%. This muscle-wasting state is the scope for the body to use muscle for energy rather than carbohydrates. But L-Glutamine supplementation can prevent this from happening. Supplementing with L-glutamine allows muscles to fight fatigue, boost strength and help repair skeletal muscles. A study published in the journal of applied physiology found that glutamine supplementation makes it possible to recover quicker from intense weight training sessions because it improves muscle hydration (J. L. Bowtell, 1999).
  • Few current pieces of researches also prove that L-Glutamine supplementation can be beneficial for people with type 2 diabetes as it improves sugar craving (Greenfield JR, 2009).


Whether looking for an increased athletic performance, to building of muscles or improving health conditions such as leaky gut or diabetes, L-glutamine should be a part of the daily diet.

Reference :

  1. Lacey, JM1,. Wilmore, DW. (1990). Is glutamine a conditionally essential amino acid?. Nutr Rev., 48(8),297-309.
  2. Ziegler, T.R. (2001). Glutamine supplementation in cancer patients receiving bone marrow transplantation and high dose chemotherapy. The Journal of Nutrition, 2578S-84S
  3. R.R.W.J. van der Hulst et al.Glutamine and the preservation of gut integrity. The Lancet, 341 (8857), P1363-1365.
  4. Bonnie Prescott (2009) Glutamine supplements show promise in treating stomach ulcers- Amino acid helps offset stomach damage caused by H. pylori bacteria, The Harvard Gazette,Health and Medicine. Retrieved from
  5. Albrecht, J., Sidoryk-Węgrzynowicz, M., Zielińska, M., & Aschner, M. (2010). Roles of glutamine in neurotransmission. Neuron Glia Biol, 6(4),263-76.
  6. Soomro I et al. (2018) Glutamine metabolism via glutaminase 1 in autosomal-dominant polycystic kidney disease, Nephrol Dial Transplant,33(8),1343-1353.
  7. J. L. Bowtell et al. (1999). Effect of oral glutamine on whole body carbohydrate storage during recovery from exhaustive exercise. Journal of Applied Physiology , Retrieved from
  8. Greenfield, JR. et al. (2009). Oral glutamine increases circulating glucagon-like peptide 1, glucagon, and insulin concentrations in lean, obese, and type 2 diabetic subjects. Am J Clin Nutr, 89(1),106-113