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L-Glutamine is an alpha-amino acid that is one of the 20 amino acids consisting proteins.
L-Glutamine is a non-essential amino acids and is also the most abundant amino acids in human bodies.
L-Glutamine is involved in many important biological processes. For example, it is a building block for the protein synthesis as one key amino acid; it is used in the biosynthesis of urea and purines for nucleic acid synthesis; it is a substrate for the biosynthesis of neurotransmitters; it is also an important sources of cellular energy generation.
CAS Number: 56-85-9
Molecular Formula: C5H10N2O3
Molecular Weight: 146.14
EINECS Number: 200-292-1
Synonyms: L-glutamine, glutamine, 56-85-9, Levoglutamide, L-(+)-Glutamine, Glutamic acid amide, Cebrogen, Stimulina, glumin, H-Gln-OH, Levoglutamid, glutamic acid 5-amide, L-Glutamide, 2-aminoglutaramic acid, (S)-2,5-Diamino-5-oxopentanoic acid, Glavamin, Miglu-P, Nutrestore, Saforis, L-2-Aminoglutaramidic acid, L-Glutamin, L-Glutamic acid gamma-amide, Glumin (amino acid), (2S)-2-amino-4-carbamoylbutanoic acid, L-2-Aminoglutaramic acid, Glutamine (VAN), Levoglutamida, Levoglutamidum, L-Glutamic acid 5-amide, FEMA No. 3684, (2S)-2,5-diamino-5-oxopentanoic acid, 2-Aminoglutaramic acid, L-, GLUTAMINE, L-, L-gln, Pentanoic acid, 2,5-diamino-5-oxo-, (S)-, Glutamine [USAN], Levoglutamidum [INN-Latin], 2,5-Diamino-5-oxopentanoic acid, (S)-, Levoglutamida [INN-Spanish], AI3-24392, glutamina, NSC 27421, Levoglutamina, L-Glutaminsaeure-5-amid, BRN 1723797, L-Glutamid, 26700-71-0, EINECS 200-292-1, MFCD00008044, UNII-0RH81L854J, ENDARI, CCRIS 9428, CHEBI:18050, HSDB 8165, 0RH81L854J, NSC-27421, CHEMBL930, gln, DTXSID1023100, d(-)-glutamine, glum, 4-04-00-03038 (Beilstein Handbook Reference), GLUTAMINE (D), Levoglutamide [DCF:INN], GLUTAMINE (MART.), GLUTAMINE [MART.], GLUTAMINE (USP-RS), GLUTAMINE [USP-RS], gamma-Glutamine, Hgln, 184161-19-1, GLUTAMINE (USP MONOGRAPH), GLUTAMINE [USP MONOGRAPH], l glutamine, Glutamine-S, Glutaminsaeure-5-amid, GLUTAMINE,L-, glutamic acid gamma-amide, (2S)-2,5-diamino-5-oxopentanoate, L-Glutamine [JAN], GLUTAMINE (L), L-Glutamic acid .gamma.-amide, CHEBI:28300, glutaminum, Glutacerebro, Gebrogen, Glutaven, Memoril, Glutamine [USAN:USP:INN], GlutaSolve, 3h-l-glutamine, Poly-L-glutamine, Q. Levoglutamide, 1wdn, (S)-glutamine, [3H]glutamine, Sympt-X, Nutrestore (TN), S(+)Glutamine, Glutamine (USP), Glutapak-10, Resource Glutasolve, [14C]glutamine, [3H]-glutamine, S(+)-Glutamine, [14C]-glutamine, H-Gln, Endari (TN), L-Glutamine-13C?, Sympt-X G.I., Glutamic acid-5-amide, Spectrum_000131, L-Glutamine [JAN], starbld0006818, L-Glutamine (standard), L-Glutaminsaure-5-amid, GLUTAMINE [INN], SpecPlus_000380, GLUTAMINE [MI], L-Glutamine (JP18), Glutamine (L-Glutamine), Spectrum2_001377, Spectrum3_001416, Spectrum4_001709, Spectrum5_000418, GLUTAMINE [VANDF], L-Glutamine, 98.5%, bmse000038, bmse001014, L-GLUTAMINE [FCC], 1-2-Aminoglutaramidic acid, L-GLUTAMINE [FHFI], SCHEMBL7453, L-GLUTAMINE [VANDF], Lopac0_000549, BSPBio_003092, GTPL723, KBioGR_002038, KBioSS_000591, DivK1c_006476, SPECTRUM1500987, S(+)-Glutamic acid 5-amide, SPBio_001334, L-[3,4-3H(N)]glutamine, LEVOGLUTAMIDE [WHO-DD], DTXCID503100, GTPL4633, GTPL4634, GLUTAMINE [ORANGE BOOK], SCHEMBL19240116, SCHEMBL23124227, BDBM18121, HY-N0390R, KBio1_001420, KBio2_000591, KBio2_003159, KBio2_005727, KBio3_002312, L-Glutamine, Cell Culture Grade, MSK1407, L-GLUTAMINE [ORANGE BOOK], HMS3261N19, HMS3264C03, Pharmakon1600-01300018, Pharmakon1600-01500987, (S)-2,5-Diamino-5-oxopentanoate, HY-N0390, (2S)-2-amino-4-carbamoylbutanoate, Tox21_500549, CCG-38853, NSC759628, NSC760081, s1749, pentanoic acid, 2,5-diamino-5-oxo-, AKOS015854078, (S)-2-Amino-4-carbamoyl-butyric acid, CS-1947, DB00130, FG02552, LP00549, NSC-759628, NSC-760081, SDCCGMLS-0066691.P001, SDCCGSBI-0050532.P005, (S)-2-Aminopentane-dioic acid 5-amide, NCGC00093936-01, NCGC00093936-02, NCGC00093936-03, NCGC00093936-04, NCGC00093936-05, NCGC00093936-15, NCGC00261234-01, AS-11765, BP-13284, DA-54895, SBI-0050532.P003, L-Glutamine, BioUltra, >=99.5% (NT), EU-0100549, G0063, L-Glutamine, SAJ special grade, >=99.0%, NS00068566, EN300-52640, C00064, D00015, D70833, G 3126, M02960, AB00173347-03, AB00173347_04, L-Glutamine, ReagentPlus(R), >=99% (HPLC), L-Glutamine, Vetec(TM) reagent grade, >=99%, L-Glutamine, Cell Culture Reagent (H-L-Gln-OH), Q181619, 7FBA778C-D6B8-495C-BFE7-1CB8EC4ABEAB, BRD-K83896451-001-01-8, BRD-K83896451-001-06-7, BRD-K83896451-001-07-5, F0001-1471, L-Glutamine, certified reference material, TraceCERT(R), Z756440074, (S)-2,5-Diamino-5-oxopentanoic acid, L-Glutamic acid 5-amide, (S)-2,5-Diamino-5-oxopentanoic acid;L-Glutamic acid 5-amide, Glutamine, United States Pharmacopeia (USP) Reference Standard, L-Glutamine, gamma-irradiated, BioXtra, suitable for cell culture, L-Glutamine, Pharmaceutical Secondary Standard; Certified Reference Material, 200-292-1, L-Glutamine, meets USP testing specifications, cell culture tested, 99.0-101.0%, from non-animal source, 2,5-Diamino-5-oxpentanoicacid;LEVOGLUTAMIDE;L(+)-GLUTAMINE;L-GLUTAMINE;L(+)-GLUTAMIC ACID-5-AMIDE;L-GLUTAMIC ACID 5-AMIDE;L-GLUTAMIC ACID AMIDE;L-GLN
L-Glutamine provides many benefits to the body such as improving gastrointestinal health, aiding the treatment of ulcer and leaky gut, promoting muscle growth, improving diabetes and blood sugar as well as aiding in the treatment of cancer.
L-Glutamine is one of the 20 amino acids encoded by the standard genetic code.
It is not recognized as an essential amino acid, but may become conditionally essential in certain situations, including intensive athletic training or certain gastrointestinal disorders.
L-Glutamines side-chain is an amide formed by replacing the side-chain hydroxyl of glutamic acid with an amine functional group, making it the amide of glutamic acid.
Its codons are CAA and CAG.
In human blood, glutamine is the most abundant free amino acid, with a concentration of about 500–900 μmol/l.
L-Glutamine is odorless, but has a slightly sweet taste L-glutamine performs a major role in DNA synthesis and sup- ports the immune system by means of glutathione synthesis.
L-Glutamine is an amino acid that plays a crucial role in many biological processes in the human body.
L-Glutamine is considered a conditionally essential amino acid, meaning that under normal circumstances, the body can produce enough of it, but during times of stress, illness, injury, or intense physical activity, the body's demand for glutamine can exceed its ability to produce it.
Structurally, L-glutamine is the L-isomer of glutamine, which is the biologically active form used by the human body in protein synthesis and various metabolic activities.
L-Glutamine serves as a building block of proteins, and it also plays a significant role in nitrogen transport between tissues, acid-base regulation in the kidneys, and fuel for rapidly dividing cells like those in the intestines and immune system.
In the intestinal lining, L-glutamine acts as a major energy source and helps maintain the integrity of the gut barrier, which prevents harmful substances from leaking into the bloodstream.
In the immune system, it supports the function of white blood cells and other immune-related processes, especially during periods of high physical or physiological stress.
L-Glutamine is also commonly used as a dietary supplement, especially by athletes and bodybuilders, to aid in muscle recovery, reduce soreness, and improve exercise performance, although research results on these effects are mixed.
Additionally, it may be used clinically to support recovery in patients who are critically ill, undergoing chemotherapy, or recovering from surgery.
White, odorless crystals or crystalline powder having a slightly sweet taste.
L-Glutamine is soluble in water and practically insoluble in alcohol and in ether.
Its solutions are acid to litmus.
L-Glutamine melts with decomposition at about 185°C.
L-Glutamine is the most abundant naturally occurring, nonessential amino acid in the human body, and one of the few amino acids that can directly cross the blood-brain barrier.
In the body, it is found circulating in the blood, as well as stored in the skeletal muscles.
L-Glutamine becomes conditionally essential (requiring intake from food or supplements) in states of illness or injury.Dietary sources
Dietary sources of L-glutamine include beef, chicken, fish, eggs, milk, dairy products, wheat, cabbage, beets, beans, spinach, and parsley.
Small amounts of free L-glutamine are also found in vegetable juices.
Aiding gastrointestinal function Glutamine-enriched diets have been linked with maintenance of gut barrier function and cell differentiation, suggesting glutamine may help to protect the lining of the gastrointestinal tract or mucosa.
People who have inflammatory bowel disease (ulcerative colitis and Crohn' s disease) may not have enough glutamine, but two clinical trials found taking glutamine supplements did not improve symptoms of Crohn' s disease.
In human blood, glutamine is the most abundant free amino acid.
The dietary sources of glutamine include especially the protein-rich foods like beef, chicken, fish, dairy products, eggs, vegetables like beans, beets, cabbage, spinach, carrots, parsley, vegetable juices and also in wheat, papaya, Brussels sprouts, celery, kale and fermented foods like miso.
The one-letter symbol Q for glutamine was assigned in alphabetical sequence to N for asparagine, being larger by merely one methylene –CH2– group.
Note that P was used for proline, and O was avoided due to similarity with D. The mnemonic Qlutamine was also proposed.
L-Glutamine is one of 20 amino acids — the building blocks of proteins.
L-Glutamine’s a nonessential amino acid, which means you get it from the foods you eat, but your body also makes it.
L-Glutamine plays key roles in your digestive and immune systems.
Prescription glutamine reduces the risk of complications from sickle cell disease.
L-Glutamine is the most abundant of 20 different amino acids in your body.
An amino acid is a building block of protein.
Proteins help with many jobs for example, proteins can help repair body tissues, keep digestive system working and help your immune system fight germs.
As a protein building block, glutamine plays a role in these functions (and others), too.
L-Glutamine is the most abundant amino acid found in the body.
L-Glutamine's made in the muscles and transferred by the blood into different organ systems.
L-Glutamine is a building block for making proteins in the body.
L-Glutamine's also needed to make other amino acids and glucose.
L-Glutamine supplements might help gut function, immune function, and other processes, especially in times of stress when the body uses more glutamine.
L-Glutamine is an α-amino acid that is used in the biosynthesis of proteins.
Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide.
L-Glutamine is classified as a charge-neutral, polar amino acid.
It is non-essential and conditionally essential in humans, meaning the body can usually synthesize sufficient amounts of it, but in some instances of stress, the body's demand for glutamine increases, and glutamine must be obtained from the diet.
L-Glutamine is encoded by the codons CAA and CAG.
It is named after glutamic acid, which in turn is named after its discovery in cereal proteins, gluten.
L-Glutamine is produced industrially using mutants of Brevibacterium flavum, which gives ca. 40 g/L in 2 days using glucose as a carbon source.
L-Glutamine synthesis from glutamate and ammonia is catalyzed by the enzyme glutamine synthetase.
The majority of glutamine production occurs in muscle tissue, accounting for about 90% of all L-Glutamine synthesized.
L-Glutamine is also released, in small amounts, by the lungs and brain.
Although the liver is capable of glutamine synthesis, its role in glutamine metabolism is more regulatory than productive, as the liver takes up glutamine derived from the gut via the hepatic portal system.
L-Glutamine is the most abundant naturally occurring, nonessential amino acid in the human body, and one of the few amino acids that can directly cross the blood–brain barrier.
Humans obtain glutamine through catabolism of proteins in foods they eat.
In states where tissue is being built or repaired, like growth of babies, or healing from wounds or severe illness, glutamine becomes conditionally essential.
L-glutamine oral powder received orphan drug designation.
The FDA granted the approval of Endari to Emmaus Medical Inc.
L-Glutamine mouthwash may be useful to prevent oral mucositis in people undergoing chemotherapy but intravenous glutamine does not appear useful to prevent mucositis in the GI tract.
L-Glutamine supplementation was thought to have potential to reduce complications in people who are critically ill or who have had abdominal surgery but this was based on poor quality clinical trials.
Supplementation does not appear to be useful in adults or children with Crohn's disease or inflammatory bowel disease, but clinical studies as of 2016 were underpowered.
Supplementation does not appear to have an effect in infants with significant problems of the stomach or intestines.
Some athletes use L-glutamine as supplement.
Studies support the positive effects of the chronic oral administration of the supplement on the injury and inflammation induced by intense aerobic and exhaustive exercise, but the effects on muscle recovery from weight training are unclear.
Stress conditions for plants (drought, injury, soil salnity) cause the synthesis of such plant enzymes as superoxide dismutase, L-ascorbate oxidase, and Delta 1 DNA polymerase.
Limiting this process, initiated by the conditions of strong soil salinity can be achieved by administering exogenous glutamine to plants.
The decrease in the level of expression of genes responsible for the synthesis of superoxide dismutase increases with the increase in glutamine concentration.
L-Glutamine is an important amino acid with many functions in the body.
It is a building block of protein and critical part of the immune system.
L-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 during times of extreme stress (the kind you experience after 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.
L-Glutamine is important for removing excess ammonia (a common waste product in the body).
L-Glutamine also helps your immune system function and may be needed for normal brain function and digestion.
L-Glutamine is a substance naturally produced in the body to help regulate cell growth and function.
There may also be man-made versions of these substances.
L-Glutamine is used together with human growth hormone and a specialized diet to treat short bowel syndrome.
L-Glutamine is also used to reduce the acute complications of sickle cell disease (blood disorder) in adults and children.
L-Glutamine is one of the 20 amino acids encoded by the genetic code and is the most abundant free amino acid in human blood.
It performs a variety of vital functions in nearly every system of the body:
As a building block of proteins, L-glutamine is necessary for tissue growth and repair.
It helps maintain muscle mass and supports cellular regeneration, making it especially important during healing or recovery.
L-glutamine plays a central role in nitrogen transport, carrying nitrogen to tissues that need it for growth and repair.
L-Glutamine also helps remove excess ammonia from the body, a toxic byproduct of protein metabolism.
Although glucose is the primary fuel for most cells, glutamine is the preferred energy source for cells in the gastrointestinal tract and the immune system.
This is especially critical during periods of catabolic stress (e.g., trauma, sepsis, intense exercise).
L-glutamine is essential for the proliferation of immune cells such as lymphocytes and macrophages.
It helps fuel immune responses and maintains the function of the gut-associated lymphoid tissue (GALT), which plays a vital role in immune defense.
The cells lining the intestines rely heavily on glutamine for energy.
L-Glutamine helps maintain the integrity of the intestinal mucosa, preventing conditions like leaky gut syndrome and reducing inflammation in the GI tract.
Melting point: 185 °C (dec.) (lit.)
Alpha: 32.25 º (c=10, 2 N HCl)
Boiling point: 265.74°C (rough estimate)
Density: 1.47 g/cm3 (20℃)
Bulk density: 640 kg/m3
FEMA: 3684 | L-GLUTAMINE
Refractive index: 6.8 ° (C=4, H2O)
Flash point: 185°C
Storage temp.: Store below +30°C.
Solubility: H2O: 25 mg/mL
Form: solution
pKa: 2.17 (at 25℃)
Color: White
pH: 5.0-6.0 (25℃, 0.1M in H2O)
Odor: at 100.00%. very mild milky custard cocoa oily
Odor Type: milky
Biological source: synthetic
Optical activity: [α]20/D +33.0±1°, c = 5% in 5 M HCl
Water Solubility: Soluble in water, dimethyl sulfoxide, and ethanol. Insoluble in methanol, ether, benzene, acetone, ethyl acetate, and chloroform.
λmax: λ: 260 nm Amax: 0.01
λ: 280 nm Amax: 0.01
Decomposition: 185 ºC
Merck: 14,4471
JECFA Number: 1430
BRN: 1723797
Stability: Moisture and light sensitive. Incompatible with moisture, strong oxidizing agents.
InChIKey: ZDXPYRJPNDTMRX-VKHMYHEASA-N
LogP: -1.67
L-Glutamine is an essential amino acid that is a crucial component of culture media that serves as a major energy source for cells in culture.
L-Glutamine is very stable as a dry powder and as a frozen solution.
In liquid media or stock solutions, however, L-glutamine degrades relatively rapidly.
Optimal cell performance usually requires supplementation of the media with L-glutamine prior to use.
L-Glutamine can exist in either of two enantiomeric forms, L-glutamine and D-glutamine.
The L-form is found in nature.
L-Glutamine contains an α-amino group which is in the protonated −NH3+ form under biological conditions and a carboxylic acid group which is in the deprotonated −COO− form, known as carboxylate, under physiological conditions.
L-Glutamine, a naturally occurring amino acid found in the human body, plays a central and indispensable role in numerous biological processes, many of which are critical for maintaining overall health, cellular integrity, and proper physiological function.
As one of the twenty standard amino acids used in the synthesis of proteins, L-glutamine is classified as a conditionally essential amino acid, which means that although the body can usually produce enough of it to meet regular demands, its synthesis may not be sufficient under certain stressful conditions—such as intense physical exertion, injury, severe illness, burns, or during times of immune compromise—making external supplementation or dietary intake necessary in those circumstances.
In terms of its chemical structure, L-glutamine is the L-isomer of glutamine, which is the biologically active form utilized in human metabolic pathways, and it features an amide group on the side chain, distinguishing it from its closely related counterpart, glutamic acid, by the substitution of a carboxylic acid group with an amide group, which significantly affects its functional properties within biochemical systems.
This structural characteristic contributes to its polarity and solubility, allowing it to be highly compatible with aqueous environments like blood plasma and intracellular fluid, and facilitates its involvement in various transport and signaling functions throughout the body.
Pharmaceutical secondary standards for application in quality control, provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards.
L-glutamine is the most abundant amino acid in the body.
L-Glutamine is essential for the synthesis of L-asparagine.
L-Glutamine also helps in muscle growth through protein synthesis and increased growth hormone levels.
L-Glutamine has been used as a GI protectant and in an attempt to enhance GI healing in conditions where GI epithelium is damaged (Parvo enteritis, chemotherapy,
A study that evaluated the efficacy of glutamine supplementation in cats with methotrexate-induced enteritis found no difference between cats supplemented with glutamine and those that were not.
L-Glutamine is synthesized by the enzyme glutamine synthetase from glutamate and ammonia.
The most relevant glutamine-producing tissue is the muscle mass, accounting for about 90% of all glutamine synthesized. Glutamine is also released, in small amounts, by the lung and the brain.
Although the liver is capable of relevant glutamine synthesis, its role in glutamine metabolism is more regulatory than producing, since the liver takes up large amounts of glutamine derived from the gut.
The most eager consumers of L-Glutamine are the cells of intestines, the kidney cells for the acid - base balance, activated immune cells, and many cancer cells.
In respect to the last point mentioned, different glutamine analogues, such as DON, Azaserine or Acivicin, are tested as anticancer drugs.
In catabolic states of injury and illness, L-Glutamine becomes conditionally essential (requiring intake from food or supplements).
L-Glutamine has been studied extensively over the past 10–15 years, and has been shown to be useful in treatment of injuries, trauma, burns, and treatment - related side effects of cancer, as well as in wound healing for postoperative patients.
L-Glutamine is also marketed as a supplement used for muscle growth in weight lifting , body building, endurance, and other sports. Evidence indicates glutamine, when orally loaded, may increase plasma HGH levels by stimulating the anterior pituitary gland.
In biological research, L-glutamine is commonly added to the media in cell culture.
However, the high level of glutamine in the culture media may inhibit other amino acid transport activities.
L-Glutamine is a conditional nonessential amino acid.
“Nonessential” means get glutamine from foods you eat, but your body makes it, too.
L-Glutamine is “conditional” because, although your body usually makes enough of it, there may be moments when you need more than your body can make.
Despite its many benefits, L-glutamine should still be used cautiously in certain populations, particularly those with hepatic encephalopathy, kidney disease, or active cancer, as the potential for increased ammonia production or tumor cell proliferation under high-glutamine conditions remains an area of ongoing investigation and debate in the scientific community.
Therefore, while L-glutamine is widely considered safe for most people when taken at appropriate doses, it is always advisable to consult a healthcare provider before beginning supplementation, especially if preexisting medical conditions or treatments are involved.
While the body can produce L-glutamine on its own, you can also obtain it from dietary sources, especially.
L-Glutamine often available in powder, capsule, or liquid form, typically marketed for athletic recovery or gut health
L-Glutamine maintains redox balance by participating in glutathione synthesis and contributing to anabolic processes such as lipid synthesis by reductive carboxylation.
L-Glutamine provides a source of carbon and nitrogen for use in other metabolic processes.
L-Glutamine is present in serum at higher concentrations than other amino acids and is essential for many cellular functions. Examples include the synthesis of nucleotides and non-essential amino acids.
One of the most important functions of glutamine is its ability to be converted into α-KG, which helps to maintain the flow of the tricarboxylic acid cycle, generating ATP via the electron carriers NADH and FADH2.
The highest consumption of glutamine occurs in the cells of the intestines, kidney cells (where it is used for acid-base balance), activated immune cells, and many cancer cells.
One of the most important physiological functions of L-glutamine is its role as a major nitrogen carrier in the bloodstream, effectively shuttling nitrogen between tissues to support anabolic processes such as tissue repair, muscle growth, and the biosynthesis of other amino acids and nucleotides.
This capacity for nitrogen donation and transport is vital for maintaining a positive nitrogen balance, particularly in individuals recovering from trauma, surgery, or infection, where tissue breakdown and catabolism are heightened, and the demand for nitrogen-rich substrates is greatly increased.
Additionally, L-glutamine serves as a primary energy source for rapidly dividing cells, particularly those found in the immune system—such as lymphocytes, macrophages, and neutrophils—as well as cells lining the gastrointestinal tract, which rely on glutamine to maintain their structural integrity, function, and resilience against pathogens and environmental stressors.
In the context of intestinal health, L-glutamine is essential for supporting the maintenance and regeneration of the intestinal epithelium, which is the first line of defense against toxins, bacteria, and undigested food particles that may otherwise breach the gut barrier and trigger systemic inflammation or immune dysfunction.
Due to its crucial roles in immune and digestive health, L-glutamine is often studied and used in clinical nutrition settings, where it is administered—sometimes intravenously—to patients suffering from critical illnesses such as sepsis, burns, trauma, or those undergoing major surgery, with the goal of reducing infection risk, preserving lean body mass, and accelerating recovery by minimizing muscle wasting and supporting immune defense mechanisms during catabolic stress.
L-Glutamine is frequently marketed as a nutritional supplement, particularly among athletes, bodybuilders, and individuals following high-intensity training programs, as it is believed to aid in reducing muscle soreness, preventing exercise-induced muscle breakdown, and promoting faster recovery between workouts by replenishing intracellular glutamine stores that are often depleted during prolonged or strenuous activity.
Although the scientific consensus on these performance-enhancing benefits remains mixed—with some studies supporting mild improvements and others finding negligible effects—its excellent safety profile and its multifaceted roles in physiology make it a popular choice for supplementation.
From a therapeutic standpoint, L-glutamine has also shown promise in managing a variety of medical conditions, including irritable bowel syndrome (IBS), inflammatory bowel diseases (IBD) like Crohn’s disease and ulcerative colitis, and oral mucositis, a painful inflammation of the mouth often experienced by cancer patients undergoing chemotherapy or radiation therapy, with glutamine supplementation potentially offering relief by enhancing mucosal healing and reducing inflammation.
Uses:
L-Glutamine is an essential amino acid that is a crucial component of culture media that serves as a major energy source for cells in culture.
L-Glutamine is very stable as a dry powder and as a frozen solution.
In liquid media or stock solutions, however, L-glutamine degrades relatively rapidly.
Optimal cell performance usually requires supplementation of the media with L-glutamine prior to use.
L-Glutamine is one of the 20 amino acids encoded by the standard genetic code.
Its codons are CAA and CAG.
L-Glutamine is a substance naturally produced in the body to help regulate cell growth and function.
There may also be man-made versions of these subs
L-glutamine is widely used in clinical and therapeutic settings because of its profound involvement in cellular repair, immune support, and gut function, making it especially valuable in treating individuals recovering from trauma, major surgery, infection, and chronic diseases that place the body under metabolic stress or result in muscle wasting and immune dysfunction.
In hospital and intensive care settings, L-glutamine is often included in enteral or parenteral nutrition formulas for critically ill patients, such as those with burn injuries, sepsis, or prolonged periods of immobilization, because it helps maintain lean body mass, supports immune cell proliferation, and accelerates tissue healing by serving as a critical substrate for rapidly dividing cells, including those in the skin, immune system, and gastrointestinal lining.
For cancer patients undergoing chemotherapy or radiotherapy, especially those who develop oral mucositis—a painful and debilitating inflammation of the mucosal lining of the mouth—L-glutamine has been used in both oral and topical forms to reduce the severity and duration of symptoms, likely by facilitating faster tissue regeneration and reducing oxidative damage caused by treatment-related stress.
In individuals with gastrointestinal disorders such as Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD) including Crohn’s disease and ulcerative colitis, or those experiencing leaky gut syndrome, L-glutamine is often used to help restore the integrity of the intestinal barrier, improve nutrient absorption, reduce inflammation, and prevent translocation of harmful substances from the gut into the bloodstream, which is a key trigger of systemic immune reactions and chronic inflammation.
Within the realm of sports performance and physical fitness, L-glutamine is a popular supplement among athletes, bodybuilders, and fitness enthusiasts, primarily due to its potential to support muscle recovery, reduce exercise-induced muscle breakdown, and minimize delayed onset muscle soreness (DOMS) that commonly follows high-intensity or resistance training sessions.
During intense physical activity, the body's glutamine levels can become depleted, especially in the skeletal muscles, leading to increased muscle fatigue and prolonged recovery times; thus, L-glutamine supplementation is believed to help replenish intramuscular stores, allowing for faster repair of damaged muscle tissue and more efficient regeneration of protein structures essential for strength and endurance.
Moreover, since prolonged or exhaustive exercise can temporarily suppress the immune system, athletes sometimes use L-glutamine to support post-exercise immune function, as it is a key fuel source for white blood cells and other immune components that help protect the body against infections during recovery periods.
Although the scientific evidence regarding performance enhancement is mixed, many users report subjective improvements in energy levels, endurance, and recovery speed, especially when L-glutamine is taken in combination with other amino acids or recovery formulas.
L-glutamine is also used by people seeking to improve general well-being, enhance digestive comfort, and maintain immune resilience, especially during times of stress, travel, or when recovering from illnesses that affect the gastrointestinal tract, such as food poisoning, viral infections, or antibiotic-associated gut dysbiosis.
Some individuals use L-glutamine as part of integrative or functional medicine approaches to support gut-brain axis health, believing that its role in maintaining intestinal barrier function can contribute to reduced systemic inflammation and potentially even impact mood, cognition, and mental clarity, although these areas remain under ongoing scientific investigation.
In the context of aging, where muscle loss (sarcopenia), immune decline, and slower healing are more common, L-glutamine is sometimes included in geriatric nutrition plans to support the preservation of muscle mass, enhance nutrient absorption, and reduce frailty, thereby improving quality of life and functional independence.
Beyond its better-known metabolic and muscular roles, L-glutamine is also critically important in neurological function, as it serves as a key precursor to both glutamate and gamma-aminobutyric acid (GABA)—two of the most abundant neurotransmitters in the human brain that are responsible for excitation and inhibition, respectively, thereby playing a vital role in maintaining cognitive balance, regulating mood, and modulating the stress response.
Because of this biochemical relationship, some researchers and clinicians have explored the potential benefits of L-glutamine supplementation in the management of anxiety, depression, and mental fatigue, particularly in individuals experiencing chronic stress or recovering from psychological trauma, as replenishing glutamine may help stabilize neurotransmitter activity, support emotional resilience, and enhance focus and mental clarity.
In neurodegenerative conditions such as Alzheimer’s disease, Parkinson’s, or even during post-stroke rehabilitation, there has been early investigation into how glutamine availability might influence brain energy metabolism and synaptic plasticity, though this remains a developing area of study with limited but promising data.
On a biochemical level, L-glutamine is deeply integrated into the cellular machinery of metabolism, serving as a carbon and nitrogen donor in various anabolic reactions, supporting the synthesis of nucleotides (purines and pyrimidines), which are essential for DNA and RNA production—a process especially crucial during periods of cell division, growth, and repair.
Due to its contribution to nucleotide biosynthesis, L-glutamine is also actively studied in oncology, both for its role in cancer metabolism—since many tumor cells exhibit "glutamine addiction" for rapid growth—and as a supportive therapy for cancer patients, helping to mitigate side effects of treatment such as gastrointestinal mucosal damage, weight loss, and immune suppression, though its use must be carefully monitored in oncologic contexts.
Furthermore, L-glutamine plays a central role in the regulation of acid-base balance, particularly in the kidneys, where it contributes to ammoniagenesis, helping the body excrete excess hydrogen ions and maintain pH homeostasis, a function that is especially important during acidosis or metabolic disorders.
In the field of nutrition and dietetics, L-glutamine is increasingly incorporated into functional foods, medical nutrition formulas, and specialized dietary supplements, not only for athletes and patients, but also for individuals with digestive sensitivities, food intolerances, or autoimmune conditions, who often benefit from its ability to support gut lining repair and reduce inflammation caused by intestinal permeability or food-related immune responses.
People following low-FODMAP diets, elimination diets, or gut-healing protocols such as the GAPS diet, SCD (Specific Carbohydrate Diet), or AIP (Autoimmune Protocol) often use L-glutamine powder as part of their daily regimen to soothe the digestive tract, promote mucosal healing, and provide a gentle, non-irritating source of amino acids that supports repair and resilience of the gastrointestinal system.
L-Glutamine is also increasingly used in postbiotic and microbiome-supporting therapies, as healthy gut bacteria interact closely with glutamine metabolism, and ensuring adequate glutamine levels may help promote microbial diversity, balance short-chain fatty acid production, and restore gut-immune homeostasis after antibiotic use or dysbiosis.
In emerging scientific research, L-glutamine is being investigated for potential applications in autoimmune conditions, such as rheumatoid arthritis, lupus, and multiple sclerosis, where it may help reduce systemic inflammation or modulate T-cell activity, given its known role in supporting both innate and adaptive immune functions and serving as a substrate for lymphocyte proliferation.
Other experimental areas of study include the use of glutamine in metabolic syndrome, insulin resistance, and type 2 diabetes, where some early studies suggest that it might influence glucose metabolism, insulin sensitivity, and fat oxidation, although these findings remain preliminary and are not yet part of standard treatment guidelines.
In pediatrics and neonatal care, particularly in premature or underweight infants, L-glutamine is sometimes added to feeding formulas to support gut maturation, immune development, and weight gain, although more research is needed to determine optimal dosing and long-term safety in these vulnerable populations.
Safety Profile:
L-Glutamine is safe in adults and in preterm infants.
Although glutamine is metabolized to glutamate and ammonia, both of which have neurological effects, their concentrations are not increased much, and no adverse neurological effects were detected.
The observed safe level for supplemental L-glutamine in normal healthy adults is 14 g/day.
Adverse effects of glutamine have been described for people receiving home parenteral nutrition and those with liver-function abnormalities.
Although glutamine has no effect on the proliferation of tumor cells, it is still possible that L-Glutamine supplementation may be detrimental in some cancer types.
Ceasing L-Glutamine supplementation in people adapted to very high consumption may initiate a withdrawal effect, raising the risk of health problems such as infections or impaired integrity of the intestine.
While L-glutamine is generally considered safe for most healthy individuals when consumed in moderate doses, excessive intake, long-term use without supervision, or use in individuals with certain medical conditions can lead to adverse effects or unexpected interactions, which should be taken seriously—especially in clinical, athletic, or supplemental contexts.
In rare cases and especially at high doses, L-glutamine may influence brain chemistry due to its metabolic relationship with the excitatory neurotransmitter glutamate.
In people who are sensitive to changes in neurochemistry, such as those with a history of seizure disorders, bipolar disorder, schizophrenia, or other neurological conditions, elevated glutamine intake may potentially worsen symptoms by contributing to excitotoxicity, a condition where excessive stimulation of neurons leads to damage or dysfunction.
Individuals with hepatic encephalopathy, a condition often related to liver disease, may also experience worsening of mental status when supplemented with L-glutamine, because impaired liver function can prevent the safe breakdown of ammonia, and glutamine metabolism can increase ammonia production, thereby exacerbating neurological symptoms like confusion, disorientation, or even coma.
One of the primary concerns with high-dose L-glutamine is its conversion to ammonia during metabolism.
Although ammonia is normally detoxified by the liver and excreted by the kidneys, in individuals with kidney disease, liver dysfunction, or certain urea cycle disorders, this process may be compromised, leading to hyperammonemia—a serious condition characterized by elevated blood ammonia levels, which can cause nausea, vomiting, mental confusion, tremors, and even life-threatening encephalopathy.
In patients with renal insufficiency or impaired excretion, excess nitrogenous waste from amino acid metabolism can place additional strain on the kidneys, and as such, glutamine supplementation is generally not recommended without direct medical supervision.
