Vitamins & Supplements · Amino acid
Glutamine
L-glutamine · also called Glutamina, L-glutamine, Gln
Glutamine is an amino acid that the body makes and uses in protein building. It is also sold as a supplement. Research shows fewer pain crises in sickle cell disease with a prescription form, and mixed results in hospital patients. Evidence for healthy people is weak. Anyone with kidney disease or diabetes should ask a doctor first.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Glutamine
Glutamine is an amino acid the body makes. Research supports a prescription form for sickle cell disease and shows mixed results in hospital patients. For healthy people the evidence is weak. Kidney cautions apply in diabetic kidney disease.
What glutamine is
Glutamine is one of the amino acids, the building blocks of protein. MedlinePlus lists it as a nonessential amino acid, which means the body can make it, and also as a conditionally essential one, which means it may be needed in illness and stress.
It is sold as a powder or capsule. A prescription-grade powder is a separate medical product. Both are L-glutamine.
When levels run low
A 2017 review says glutamine becomes deficient in critical illness, trauma, infection, cancer and gut disorders. It is also a precursor of arginine. This is why hospital teams have tested it in feeding.
That does not show that healthy people are short of it or that pills help them.
Food and pills
No source read for this page gave the amount of glutamine in foods, so none is stated here. The body also makes its own glutamine.
The results on this page are for glutamine given as a hospital feed, a prescription powder or an oral supplement, not for foods.
What the research shows
The best evidence is for a prescription L-glutamine in sickle cell disease: one maker-funded trial showed fewer pain crises. In hospital patients, a Cochrane review found fewer infections, but a later large trial in people with organ failure found more deaths with glutamine.
A single trial in post-infection IBS-D found large benefits, but it needs repeating. No benefit was found in premature babies. For muscle and recovery in healthy people, the evidence is weak.
At a glance
Traditional uses history, not proof
- An amino acid made by the body
- Sold as powders and capsules for gut, muscle and recovery claims
Studied for research
- Normal role and low levels in illness, moderate certainty
- Sickle cell disease (prescription product), moderate certainty
- Critical illness and major surgery, mixed
- Post-infection IBS with diarrhoea, low certainty
- Mouth sores in cancer treatment, moderate certainty
- Muscle and recovery, insufficient
- Premature babies, evidence against
Main compounds
- L-glutamine
- Pharmaceutical-grade L-glutamine (prescription)
Common forms
- Powder and capsules (supplement)
- Prescription oral powder (sickle cell disease)
- Hospital nutrition by vein or tube
Research links: 2018 phase 3 trial: L-glutamine in sickle cell disease · 2014 Cochrane review: glutamine for critically ill adults (53 trials) · 2013 trial: glutamine and antioxidants in critical illness · 2019 trial: glutamine for post-infection IBS · 2019 review: kidney safety of amino acid supplements · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Glutamine (L-glutamine), an amino acid
- Common names
- Glutamine (English); L-glutamine (English); Gln (English (abbreviation)); Glutamina (Spanish)
- Family or group
- Amino acid. MedlinePlus lists glutamine as nonessential and also as conditionally essential, meaning it is usually not needed from food except in illness and stress.
- Look-alikes and adulterants
- Name: Glutamic acid (glutamate); Note: A different amino acid. MedlinePlus lists glutamic acid and glutamine separately as nonessential amino acids.; Name: Arginine; Note: A related conditionally essential amino acid; glutamine is a precursor of arginine (2017 review).
- Sustainability and conservation
- Not assessed.
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| L-glutamine (powder or capsules) | amino acid | Not read from a source. | The form sold as a supplement; tested in the IBS trial as an oral dietary supplement. 12 | Human data |
| Pharmaceutical-grade L-glutamine | amino acid, prescription product | Not read from a source. | Tested in the sickle cell phase 3 trial; a medical product. 6 | Human data |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Conditional need in stress | Not specified in the sources read | A 2017 review says glutamine, a precursor of arginine, becomes deficient in critical illness, trauma, infection, cancer and gut disorders. 5 | Human data |
| Oxidative stress in sickle red cells | NAD (reduced form) | The trial abstract says oral L-glutamine raised the share of reduced NAD in sickle red cells, which probably reduces oxidative stress. This is the authors' explanation; it was not shown to cause the fewer pain crises. 6 | Human data |
| Gut permeability | Not specified | In the IBS trial, raised gut permeability (lactulose/mannitol ratio) was normalised in the glutamine group only. 12 | Human data |
Absorption, metabolism and elimination
- Absorption
- Not described in the sources read.
- Distribution
- Not described in the sources read.
- Metabolism
- A 2017 review says glutamine is a precursor of arginine.
- Elimination
- Not described in the sources read.
- Bioavailability
- Not compared across forms or with food in the sources read.
Isolated compounds versus whole extracts
All the benefits above come from glutamine given as a medical product, by vein or tube in hospital, or as an oral supplement. No source read gave glutamine amounts in foods or compared food glutamine with pills.
Nutritional composition
No food glutamine amounts were read from USDA or any other source, so none are given. Protein-containing foods supply amino acids in general, and the body also makes glutamine itself (MedlinePlus).
3 moderate certainty1 mixed findings1 low certainty2 not enough evidence1 evidence against
What was looked at
The 8 benefits and uses checked for Glutamine, each with how strong the evidence is. Tap one to open it.
- Normal role and low levels in serious illnessModerate certainty
- Sickle cell disease (prescription product)Moderate certainty
- Critical illness and major surgery (hospital use)Mixed findings
- Diarrhoea-type irritable bowel syndrome after a gut infectionLow certainty
- Mouth sores from cancer treatmentModerate certainty
- Illness and death in premature babiesEvidence against
- Short bowel syndromeNot enough evidence
- Muscle mass, strength and recovery in healthy peopleNot enough evidence
Lab markers tracked in the studies
Pain crises in sickle cell diseaseHospital-acquired infectionsDeaths in critical illnessIBS severity scoreGut permeability (leaky gut)Severe mouth sores in cancer treatment
What is Glutamine good for?
The main studied uses and how strong the human evidence is for each. Several results are for hospital care or a prescription product, not for powders bought over the counter.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Normal role and low levels in serious illness
Moderate certaintyGlutamine is one of the most abundant amino acids in the body. The body makes it, so it is not an essential amino acid. MedlinePlus lists it as conditionally essential: usually not needed from food, but it may be needed in times of illness and stress. Levels can fall in critical illness, trauma, infection, cancer and gut disorders.
2 studiesNot applicable; the sources describe the body's own glutamine.
Studies, doses and limits
What the trials found
A 2017 review (abstract read) says glutamine is one of the most abundant amino acids in the body and, like arginine, becomes deficient in several stress states: critical illness, trauma, infection, cancer and gut disorders. MedlinePlus classes glutamine as nonessential and also as conditionally essential. Neither source shows that glutamine pills correct this in healthy people.
Results
Glutamine is made by the body. Low levels can occur in serious illness. This does not show that pills help.
Effect sizes as reported
No numbers in the sources read.
Why this rating
Two reviews and one reference page agree on the idea. They are descriptions, not trials of pills.
Who was studied
General description; people in stress states such as critical illness.
Limits
Narrative reviews and an encyclopedia page; no dose or outcome data.
Why researchers looked
To understand why glutamine is given in hospital nutrition and sold as a supplement.
Traditional use
A normal body role is different from showing that extra pills help. This page does not claim that healthy people need a supplement.
Proposed mechanism Review statement
The 2017 review says glutamine is a precursor of arginine and is low in several stress states; the sources read give no more detail on how it works.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab: glutamine in very sick people has had mixed and in one trial worse results.
Sickle cell disease (prescription product)
Moderate certaintyIn a 48-week trial of 230 people aged 5 to 58 with sickle cell anaemia or a related type, a prescription-grade L-glutamine powder was linked to fewer pain crises and fewer hospital stays than placebo. Two thirds also took hydroxyurea. It was tested under medical care and funded by the maker. This does not apply to general supplement use.
2 studiesPharmaceutical-grade L-glutamine powder, a medical product; it is not…
Studies, doses and limits
What the trials found
A phase 3, randomised, double-blind, placebo-controlled trial (Niihara 2018, NEJM; 230 people; 152 on glutamine, 78 on placebo; 48 weeks). Median pain crises were 3.0 with glutamine and 4.0 with placebo (P=0.005). Median hospitalisations were 2.0 and 3.0 (P=0.005). Nausea, non-cardiac chest pain, fatigue and muscle or bone pain were more common with glutamine. A 2026 systematic review found the pain-crisis rate ratio was 0.75 (95% CI 0.62 to 0.90) in this pivotal trial and said the evidence leans on that one core trial.
Results
Fewer pain crises and hospital stays than placebo in one trial, in people with sickle cell disease only.
Effect sizes as reported
Median crises 3.0 vs 4.0; hospitalisations 2.0 vs 3.0; rate ratio 0.75 (0.62 to 0.90).
Why this rating
One well-designed trial plus a later systematic review that relies on it; maker-funded; no independent repeat was read.
Form and dose studied
Pharmaceutical-grade L-glutamine powder, a medical product; it is not the same as sports powders.
Who was studied
People with a sickle cell diagnosis, aged 5 to 58.
Limits
Funded by the maker (Emmaus Medical). One core trial. Not tested in people without sickle cell disease.
Why researchers looked
Sickle cell red cells are under heavy oxidative stress, and researchers tested whether glutamine could help.
Traditional use
Not a traditional remedy; a prescription medicine product.
Proposed mechanism Human mechanism hypothesis
The trial abstract says glutamine raised the share of the reduced form of NAD in sickle red cells, which probably lowers oxidative stress. This is the authors' explanation, not proof.
A proposed mechanism does not show that the effect happens in people.
Side effects included nausea, chest pain and fatigue. Used only with a doctor.
Critical illness and major surgery (hospital use)
Mixed findingsA Cochrane review of 53 trials (4,671 people) in critically ill or major-surgery patients found fewer hospital infections with glutamine. Deaths did not clearly differ. A later large trial in people with organ failure found more deaths with glutamine. This is a hospital-team matter, not a home powder.
2 studiesGiven by vein and by feeding tube by hospital teams; not comparable t…
Studies, doses and limits
What the trials found
Cochrane 2014 (53 trials, 4,671 people): fewer hospital-acquired infections (RR 0.79, 95% CI 0.71 to 0.87, moderate-quality evidence); short-term deaths not clearly different (RR 0.89, 0.78 to 1.02, low quality); long-term deaths no different (RR 1.00); hospital stay 3.46 days shorter (low quality); ICU stay slightly longer (0.18 days); fewer ventilator days (0.69 shorter). The review rated overall risk of bias as high and suspected publication bias. REDOXS (Heyland 2013, NEJM; 1,223 adults with organ failure on ventilators): 28-day deaths were 32.4% with glutamine vs 27.2% without (adjusted OR 1.28, 1.00 to 1.64, P=0.05), and hospital and 6-month deaths were significantly higher. Infections and organ failure were not reduced.
Results
Mixed. Pooled small trials saw fewer infections; the largest trial in the sickest patients saw more deaths.
Effect sizes as reported
Infections RR 0.79; short-term deaths RR 0.89; REDOXS adjusted OR 1.28 for 28-day death.
Why this rating
The Cochrane review found moderate-quality evidence of fewer infections but had high overall risk of bias. The large REDOXS trial pointed the other way for deaths.
Form and dose studied
Given by vein and by feeding tube by hospital teams; not comparable to home powders.
Who was studied
Critically ill adults and adults having major elective surgery (REDOXS: multiple organ failure).
Limits
Review includes small, older trials with high bias risk. The Cochrane review's searches ended in 2013, so it does not include later trials.
Why researchers looked
Glutamine levels fall in critical illness, so researchers tested giving it in hospital feeding.
Traditional use
Used in hospital nutrition, mostly by vein or by feeding tube.
Proposed mechanism None stated
Not established; the reviews say glutamine is low in these patients and that adding it was tested, not that low levels explain the results.
A proposed mechanism does not show that the effect happens in people.
Higher deaths in one large trial of people with organ failure; see the Safety tab.
Diarrhoea-type irritable bowel syndrome after a gut infection
Low certaintyOne 8-week trial in 106 adults who developed diarrhoea-type IBS with leaky gut after an infection found much larger improvements with a glutamine supplement than with placebo. The effect was very large, so the authors call for bigger trials. Only one trial was read, so this is not settled.
1 studiesOral glutamine supplement, studied for 8 weeks.
Studies, doses and limits
What the trials found
Zhou 2019, Gut: randomised, double-blind, placebo-controlled; 54 on glutamine and 52 on placebo completed 8 weeks. The main goal (IBS severity score down 50 points or more) was reached by 43 (79.6%) on glutamine and 3 (5.8%) on placebo. Daily bowel movements, stool form and gut permeability also improved (P<0.0001). Side effects were low and similar in the two groups, and none was serious.
Results
Large improvement in one trial in a narrow group; needs repeating.
Effect sizes as reported
79.6% vs 5.8% reached the main goal.
Why this rating
One trial, a very large effect, only completers reported in the abstract, narrow group. Needs independent repeat.
Form and dose studied
Oral glutamine supplement, studied for 8 weeks.
Who was studied
Adults with post-infection diarrhoea-type IBS with raised gut permeability.
Limits
Single trial; narrow group; not tested in other kinds of IBS or in healthy people.
Why researchers looked
Glutamine is a fuel for gut lining cells, and leaky gut is common after infection, so it was tested.
Traditional use
Gut and immunity claims for glutamine powders are common; this trial is one of the few human tests.
Proposed mechanism Human measure
The authors measured gut permeability and report it normalised with glutamine; why that happened was not established.
A proposed mechanism does not show that the effect happens in people.
Side effects were similar to placebo in this trial.
Mouth sores from cancer treatment
Moderate certaintyA 2023 umbrella review of 26 meta-analyses found that glutamine, honey and propolis can lower the incidence of severe mouth sores (oral mucositis) in people having cancer treatment, rated moderate-quality evidence. The abstract does not say how glutamine was given. The authors say better trials are needed.
1 studiesNot stated in the abstract.
Studies, doses and limits
What the trials found
Amiri Khosroshahi 2023, Nutr Rev: an umbrella review of 26 meta-analyses of randomised trials. Honey, glutamine and propolis reduced severe oral mucositis (moderate-quality evidence by the reviewers' GRADE rating). Zinc reduced mucositis overall, with low certainty. Vitamin E, curcumin and probiotics showed no significant effect.
Results
Fewer severe mouth sores in pooled analyses.
Effect sizes as reported
No numbers in the abstract.
Why this rating
The reviewers graded it moderate. But it is a review of reviews and the form and route of glutamine are not stated in the abstract.
Who was studied
People with cancer having treatment.
Limits
A review of reviews; no numbers read; form and route not known from the abstract.
Why researchers looked
Cancer treatment often causes painful mouth sores, so nutrition options are tested.
Traditional use
Supportive care under a cancer team.
Proposed mechanism None stated
Not established.
A proposed mechanism does not show that the effect happens in people.
Anyone in cancer care should ask their team before using supplements.
Illness and death in premature babies
Evidence againstA Cochrane review of 12 trials (2,877 premature babies) found no effect of glutamine on deaths, serious infection or a bowel emergency called necrotising enterocolitis. Three trials found no effect on development to age 2. The authors found no important benefit.
1 studiesBy mouth, tube or vein in hospital.
Studies, doses and limits
What the trials found
Moe-Byrne 2016, Cochrane: 12 randomised trials, 2,877 preterm infants, 6 using glutamine by mouth or tube and 6 by vein. Typical RR for death 0.97 (95% CI 0.80 to 1.17). No effect on invasive infection or necrotising enterocolitis. No effect on development at 18 to 24 months in three trials. Trials were generally of good methodological quality.
Results
No benefit found.
Effect sizes as reported
Mortality typical RR 0.97 (0.80 to 1.17).
Why this rating
Trials were of generally good quality and found no benefit.
Form and dose studied
By mouth, tube or vein in hospital.
Who was studied
Preterm infants.
Limits
Hospital newborn care only; says nothing about adults.
Why researchers looked
Glutamine was tried because premature babies may have low levels.
Traditional use
Hospital care for newborns.
Proposed mechanism None stated
Not established.
A proposed mechanism does not show that the effect happens in people.
Not a home use.
Short bowel syndrome
Not enough evidenceA Cochrane review of 5 trials looked at growth hormone with or without glutamine in adults with short bowel syndrome. There were short-lived gains in weight and absorption that faded after treatment stopped. Glutamine's own effect could not be separated out, so the evidence is inconclusive.
1 studiesNot applicable.
Studies, doses and limits
What the trials found
Wales 2010, Cochrane: 5 randomised trials. Growth hormone with or without glutamine increased weight (MD 1.66 kg, 95% CI 0.69 to 2.63) and lean mass (MD 1.93 kg, 0.97 to 2.90) in the short term, but effects returned to baseline soon after stopping. The authors say the evidence is inconclusive.
Results
Short-lived gains; glutamine alone not separated.
Effect sizes as reported
Weight +1.66 kg; lean mass +1.93 kg (with growth hormone).
Why this rating
Glutamine was combined with growth hormone; only 5 small, older trials.
Who was studied
Adults with short bowel syndrome.
Limits
Combination with growth hormone; older review.
Why researchers looked
People with a very short gut cannot absorb enough food, so extra treatments are tested.
Traditional use
Specialist hospital care.
Proposed mechanism None stated
Not established.
A proposed mechanism does not show that the effect happens in people.
Specialist care only.
Muscle mass, strength and recovery in healthy people
Not enough evidenceA 2019 review of muscle supplements rated the evidence for glutamine as weak or scarce. Creatine and protein did better. Claims that glutamine speeds recovery or protects immunity in healthy active people were not backed by any trial read for this page.
1 studiesNot applicable.
Studies, doses and limits
What the trials found
Valenzuela 2019, Eur J Nutr (narrative review): evidence level C (weak or scarce) for glutamine on muscle mass or strength. No numbers were given in the abstract. No source read supports recovery or immunity benefits in healthy people.
Results
No reliable benefit shown.
Effect sizes as reported
No numbers in the abstract.
Why this rating
A broad review rated the evidence weak or scarce; no trial was read.
Who was studied
Healthy people.
Limits
Abstract only; no glutamine-specific trials read.
Why researchers looked
Glutamine is popular in sports nutrition, so reviewers looked for trials.
Traditional use
Sports nutrition marketing.
Proposed mechanism None stated
Not established.
A proposed mechanism does not show that the effect happens in people.
Kidney note on the Safety tab for people with diabetic kidney disease.
Connections to the rest of health
How Glutamine connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Immune System | Biological association | Moderate certainty | Studied for: Normal role and low levels in serious illness Studied for: Sickle cell disease (prescription product) | 5 13 6 11 8 3 1 4 |
| Digestive System | Biological association | Moderate certainty | Studied for: Normal role and low levels in serious illness Studied for: Critical illness and major surgery (hospital use) | 5 13 8 3 12 1 4 10 |
| Blood | Biological association | Moderate certainty | Studied for: Sickle cell disease (prescription product) | 6 11 |
| Musculoskeletal System | Biological association | Not enough evidence | Studied for: Muscle mass, strength and recovery in healthy people | 9 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Diabetic nephropathy | Documented risk | A review reports raised creatinine and glomerulosclerosis with glutamine in diabetic kidney disease. A review reports raised creatinine and kidney scarring with glutamine in diabetic kidney disease. Preparation or compound: Glutamine supplements |
2 | |
| Sickle cell anaemia | Clinical trial evidence | Fewer pain crises in one maker-funded trial. Fewer pain crises with prescription L-glutamine in one maker-funded trial. Preparation or compound: Prescription L-glutamine |
6 11 | |
| Critical illness | Mixed findings | Fewer infections in pooled trials but more deaths in one large trial. Preparation or compound: Hospital glutamine |
8 3 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Pain crises in sickle cell disease | Biological association | Moderate certainty | Measured in trials: fewer with glutamine (one trial). A lab change is not the same as a health benefit. | 6 |
| Hospital-acquired infections | Biological association | Moderate certainty | Measured in trials: fewer with glutamine (pooled trials). A lab change is not the same as a health benefit. | 8 |
| Deaths in critical illness | Biological association | Mixed findings | Measured in trials: no clear difference in pooled trials; higher in REDOXS. A lab change is not the same as a health benefit. | 3 |
| IBS severity score | Biological association | Low certainty | Measured in trials: lower with glutamine (one trial). A lab change is not the same as a health benefit. | 12 |
| Gut permeability (leaky gut) | Biological association | Low certainty | Measured in trials: normalised with glutamine (one trial). A lab change is not the same as a health benefit. | 12 |
| Severe mouth sores in cancer treatment | Biological association | Moderate certainty | Measured in trials: fewer with glutamine (pooled analyses). A lab change is not the same as a health benefit. | 1 |
K. Biological pathways
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| L-glutamine (powder or capsules) | Biological association | Human | The form sold as a supplement; tested in the IBS trial as an oral dietary supplement. | 12 |
| Pharmaceutical-grade L-glutamine | Biological association | Human | Tested in the sickle cell phase 3 trial; a medical product. | 6 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).
Evidence at a glance: what the research found for 8 outcomes
Each outcome below is one thing researchers measured. Certainty is how far the evidence can be trusted, not how well it works. The full studies are on the next tab.
The evidence
The research centre for Glutamine. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our existing glutamine summary, read MedlinePlus, and re-read PubMed abstracts for the trials and reviews cited. Only abstracts were read for studies. The NIH Office of Dietary Supplements and FDA pages could not be read and are marked unverified.
Study library: every study we checked 13
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Amiri Khosroshahi 2023 Nutritional interventions for the prevention and treatment of cancer therapy-induced oral mucositis: an umbrella review of systematic reviews and meta-analyses. Nutr Rev · PMID 36763701 · DOI |
Umbrella review |
People with cancer on treatment; 26 meta-analyses | Honey, glutamine, propolis, zinc and others (glutamine as pooled; route and form not stated in the abstract) Not summarised Varies · vs Placebo or usual care |
Glutamine, honey and propolis reduced the incidence of severe mouth sores, rated moderate-quality evidence. Vitamin E, curcumin and probiotics did not. The authors say well-designed trials are needed to confirm. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Incidence of severe mouth sores (oral mucositis) Limitations: An umbrella review of other reviews; glutamine form and route not stated in the abstract. Funding and conflicts: Not stated in the abstract. Registration: PROSPERO CRD42022301010 Read: abstract |
| Davani-Davari 2019 The Renal Safety of L-Carnitine, L-Arginine, and Glutamine in Athletes and Bodybuilders. J Ren Nutr · PMID 30341034 · DOI |
Narrative review |
Review of kidney safety; 5 glutamine studies were included (healthy athletes; one setting was diabetic kidney disease) | Glutamine supplements Powder or capsule (as studied) Short term 20 to 30 g within a few hours; long term 0.1 g per kg four times daily for 2 weeks (as stated in the abstract) Hours to 2 weeks |
In healthy athletes, short-term and 2-week glutamine use was linked to no significant adverse effects. In diabetic kidney disease, glutamine can cause glomerulosclerosis and raise serum creatinine. The authors call for more data. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Kidney function and kidney damage Limitations: Narrative review of few studies (5 for glutamine); abstract only read; not a systematic review of harms. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Heyland 2013 A randomized trial of glutamine and antioxidants in critically ill patients. N Engl J Med · PMID 23594003 · DOI |
Randomised controlled trial |
1223 Adults on ventilators with failure of several organs in 40 intensive care units (Canada, US, Europe) |
Glutamine and/or antioxidants, by vein and by feeding tube Intravenous plus enteral Started within 24 hours of ICU admission · vs Placebo (2-by-2 design) |
Deaths at 28 days were 32.4% with glutamine vs 27.2% without (adjusted OR 1.28, borderline P=0.05). Hospital and 6-month deaths were significantly higher with glutamine. No effect on organ failure or infections. Antioxidants did not change deaths. Adjusted OR 1.28 for 28-day death with glutamine (95% CI 1.00 to 1.64) Methods, limits and fundingOutcomes: 28-day deaths (main); hospital and 6-month deaths; organ failure; infections Limitations: Very sick people with organ failure only; high hospital-given amounts; does not apply to healthy people taking powders. Funding and conflicts: Funded by the Canadian Institutes of Health Research (public funder). Registration: NCT00133978 Read: abstract |
| Moe-Byrne 2016 Glutamine supplementation to prevent morbidity and mortality in preterm infants. Cochrane Database Syst Rev · PMID 27089158 · DOI |
Systematic review meta analysis |
2877 Preterm infants; 12 randomised trials (6 by mouth or tube, 6 by vein) |
Glutamine added to feeds or given by vein Enteral or parenteral Varies by trial Birth to hospital discharge · vs No glutamine |
No effect on deaths (typical RR 0.97), invasive infection or necrotising enterocolitis. Three trials found no effects on development at 18 to 24 months and beyond. The authors say there is no evidence of important benefit. Mortality typical RR 0.97 (0.80 to 1.17) Methods, limits and fundingOutcomes: Deaths; infection; necrotising enterocolitis; development at 18 to 24 months Limitations: Hospital-given glutamine in newborns. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Morris 2017 Acquired Amino Acid Deficiencies: A Focus on Arginine and Glutamine. Nutr Clin Pract · PMID 28388380 · DOI |
Narrative review |
Review of arginine and glutamine in stress states | Glutamine (body levels) |
Glutamine is one of the most abundant amino acids in the body. It becomes deficient in several conditions of stress, including critical illness, trauma, infection, cancer and gut disorders. It is a precursor of arginine. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Why glutamine becomes low in illness Limitations: A narrative review; abstract only read; does not show that pills help. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Niihara 2018 A Phase 3 Trial of l-Glutamine in Sickle Cell Disease. N Engl J Med · PMID 30021096 · DOI |
Randomised controlled trial |
230 Children and adults aged 5 to 58 with sickle cell anaemia or sickle beta-zero thalassaemia and 2 or more pain crises in the previous year; about two thirds also took hydroxyurea |
Pharmaceutical-grade L-glutamine powder by mouth Powder, pharmaceutical grade (not a general supplement) 0.3 g per kg of body weight, twice daily (as stated in the abstract) 48 weeks · vs Placebo |
Fewer pain crises (median 3.0 vs 4.0, P=0.005) and fewer hospitalisations (median 2.0 vs 3.0, P=0.005) than placebo. Low-grade nausea, non-cardiac chest pain, fatigue and muscle or bone pain were more common with glutamine. Median pain crises 3.0 vs 4.0; hospitalisations 2.0 vs 3.0 (P=0.005 for both (confidence intervals not in the abstract)) Methods, limits and fundingOutcomes: Number of pain crises; hospitalisations; side effects Limitations: Funded by the product maker; abstract does not report long-term follow-up; applies to people with a sickle cell diagnosis, not to the general public. Funding and conflicts: Funded by Emmaus Medical, the maker of the product tested. Registration: NCT01179217 Read: abstract |
| Shao 2008 Risk assessment for the amino acids taurine, L-glutamine and L-arginine. Regul Toxicol Pharmacol · PMID 18325648 · DOI |
Narrative review |
Healthy adults in published human trials | L-glutamine supplements Observed Safe Level for glutamine: 14 g a day (this is the review authors figure, not an official limit) Varies by trial |
No consistent pattern of harm was seen, so the usual upper-limit method could not be used. Using another method (Observed Safe Level), the authors found strong evidence of no adverse effects up to 14 g a day of glutamine in healthy adults. Higher amounts were tested without harm but the data were not enough to call them safe long term. Observed Safe Level 14 g a day (glutamine) (Not applicable) Methods, limits and fundingOutcomes: Safe intake level Limitations: A review from 2008, not a regulator ruling. Healthy adults only. Funding and affiliations not in the abstract. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Tao 2014 Glutamine supplementation for critically ill adults. Cochrane Database Syst Rev · PMID 25199493 · DOI |
Systematic review meta analysis |
4671 Adults with critical illness or having elective major surgery; 53 trials |
Glutamine given by hospital teams, by vein or by feeding tube (as pooled) Intravenous or enteral nutrition Varies by trial; not summarised here Varies by trial · vs No glutamine or placebo |
Fewer infections (RR 0.79, moderate-quality evidence). Short-term deaths not clearly different (RR 0.89, low quality); long-term deaths no different (RR 1.00). Hospital stay was 3.46 days shorter (low quality), ICU stay 0.18 days longer, ventilator days 0.69 shorter. Serious side effects were imprecise. The authors say overall risk of bias was high and publication bias was suspected. Infections RR 0.79; short-term deaths RR 0.89; long-term deaths RR 1.00; hospital stay MD -3.46 days; ventilation MD -0.69 days (Infections 0.71 to 0.87; short-term deaths 0.78 to 1.02; long-term deaths 0.89 to 1.12; hospital stay -4.61 to -2.32 days; ventilation -1.37 to -0.02 days) Methods, limits and fundingOutcomes: Hospital-acquired infections; deaths; hospital and ICU stay; days on a ventilator; side effects Limitations: High overall risk of bias, suspected publication bias, moderate to large differences between trials (I2 up to 63%). Written before the 2013 REDOXS trial results were added (searches to 2013). Funding and conflicts: Not stated in the abstract. Read: abstract |
| Valenzuela 2019 Supplements with purported effects on muscle mass and strength. Eur J Nutr · PMID 30604177 · DOI |
Narrative review |
Healthy people and people with muscle loss; many supplements reviewed | Many supplements; glutamine was one |
The review rated the evidence for glutamine as weak or scarce (its evidence level C). Creatine, protein and polyunsaturated fats were rated higher. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Muscle mass and strength Limitations: A broad narrative review; abstract only read; no glutamine-specific numbers. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Wales 2010 Human growth hormone and glutamine for patients with short bowel syndrome. Cochrane Database Syst Rev · PMID 20556765 · DOI |
Systematic review meta analysis |
Adults with short bowel syndrome; 5 randomised trials | Growth hormone with or without glutamine Not separated Not summarised Short term · vs Control |
Growth hormone with or without glutamine gave some short-lived gains (weight +1.66 kg, lean mass +1.93 kg). Benefits faded after treatment stopped. The authors call the evidence inconclusive. Glutamine alone was not separated out. Weight MD 1.66 kg; lean mass MD 1.93 kg (Weight 0.69 to 2.63; lean mass 0.97 to 2.90) Methods, limits and fundingOutcomes: Weight, lean mass, nutrient absorption, nutrition-by-vein needs Limitations: Glutamine was combined with growth hormone, so its own effect cannot be judged; only 5 small trials; older review (2010). Funding and conflicts: Not stated in the abstract. Read: abstract |
| Wang 2026 Benefit-risk of voxelotor, crizanlizumab, and l-glutamine in sickle cell disease: A systematic review. Am J Med Sci · PMID 42628795 · DOI |
Systematic review |
People with sickle cell disease; 8 studies in total across three medicines | L-glutamine (prescription), compared with two other medicines Prescription Not summarised Varies |
In the pivotal L-glutamine trial the pain-crisis rate was lower (rate ratio 0.75). The review did not pool results and says the evidence rests mostly on one core trial per medicine. Rate ratio 0.75 for L-glutamine pain crises (95% CI 0.62 to 0.90) Methods, limits and fundingOutcomes: Vaso-occlusive (pain) crisis burden Limitations: Systematic review with no pooled analysis; one main trial behind the glutamine finding; abstract only. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Zhou 2019 Randomised placebo-controlled trial of dietary glutamine supplements for postinfectious irritable bowel syndrome. Gut · PMID 30108163 · DOI |
Randomised controlled trial |
106 Adults who developed diarrhoea-predominant irritable bowel syndrome with leaky gut after a gut infection; 106 finished the trial |
Glutamine supplement by mouth Oral supplement 5 g three times a day (as stated in the abstract) 8 weeks · vs Placebo |
43 of 54 on glutamine (79.6%) and 3 of 52 on placebo (5.8%) reached the main goal. Secondary measures also improved, and leaky gut was normalised only with glutamine. Side effects were low and similar, with no serious ones. 79.6% vs 5.8% reached the main goal (P<0.0001 for secondary measures (confidence intervals not in the abstract)) Methods, limits and fundingOutcomes: IBS severity score (50 points or more lower); bowel movements; stool form; gut permeability Limitations: A very large effect from one trial; the authors say larger trials are needed. A narrow group (post-infection IBS with leaky gut). Only people who finished were counted in the abstract. Funding and conflicts: US public research funding (NIH and Government support noted in the record). Registration: NCT01414244 Read: abstract |
| s-medlineplus-aminoacids MedlinePlus Medical Encyclopedia: Amino acids · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text |
What we do not know yet
- No trial was read showing that glutamine pills help healthy people.
- No independent repeat of the sickle cell or IBS trials was read.
- No food glutamine amounts were read.
- The NIH Office of Dietary Supplements page was blocked, so no official US statement was read.
- No interaction, pregnancy, liver disease or contamination sources were read.
- Glutamine for diabetes, sleep, mood and wound healing was not researched.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue before the page changes.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Other 6
Pain crises in sickle cell disease
Fewer with glutamine (one trial) in trials
How often a person with sickle cell disease has a pain (vaso-occlusive) crisis.
Moderate certaintyResults and what it means
Why it was measured
To see whether glutamine lowers the number of crises.
Statistical vs. clinical meaning
A meaningful difference in a measure patients care about, from one maker-funded trial.
Safety implication
Side effects included nausea and chest pain.
| Study | Result | People | Product |
|---|---|---|---|
| 6 | Median 3.0 vs 4.0 crises over 48 weeks (P=0.005) | 230 people, ages 5 to 58 | Pharmaceutical-grade L-glutamine |
Hospital-acquired infections
Fewer with glutamine (pooled trials) in trials
New infections that start during a hospital stay.
Moderate certaintyResults and what it means
Why it was measured
To see whether glutamine in hospital feeding reduces infections.
Statistical vs. clinical meaning
Moderate-quality evidence; high risk of bias overall.
Safety implication
A large trial in organ failure saw no reduction in infections.
| Study | Result | People | Product |
|---|---|---|---|
| 8 | RR 0.79 (95% CI 0.71 to 0.87), 33 trials, 2,303 people | Critically ill or major-surgery adults | Glutamine in hospital feeding |
Deaths in critical illness
No clear difference in pooled trials; higher in REDOXS in trials
Deaths in hospital or within 28 days to 6 months.
Mixed findingsResults and what it means
Why it was measured
To check whether glutamine helps or harms the sickest patients.
Statistical vs. clinical meaning
Pooled trials found no clear benefit on deaths; the largest trial found more deaths.
Safety implication
This is the key safety signal for glutamine in very sick people.
| Study | Result | People | Product |
|---|---|---|---|
| 3 | 28-day deaths 32.4% vs 27.2% (adjusted OR 1.28, 1.00 to 1.64) | 1,223 adults with organ failure on ventilators | Glutamine and/or antioxidants |
IBS severity score
Lower with glutamine (one trial) in trials
A questionnaire score of how bad irritable bowel symptoms are.
Low certaintyResults and what it means
Why it was measured
To see whether glutamine eases IBS symptoms.
Statistical vs. clinical meaning
A very large effect from one trial.
Safety implication
Side effects similar to placebo in this trial.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | 43 of 54 (79.6%) vs 3 of 52 (5.8%) had a fall of 50 points or more | 106 adults with post-infection IBS-D | Oral glutamine for 8 weeks |
Gut permeability (leaky gut)
Normalised with glutamine (one trial) in trials
How easily substances cross the gut wall, measured in urine.
Low certaintyResults and what it means
Why it was measured
To see whether glutamine improves gut barrier function.
Statistical vs. clinical meaning
Supports a possible mechanism but comes from one trial.
Safety implication
None noted in the abstract.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Lactulose/mannitol ratio fell from 0.11 to 0.05 (P<0.0001) in the glutamine group | 106 adults with post-infection IBS-D | Oral glutamine for 8 weeks |
Severe mouth sores in cancer treatment
Fewer with glutamine (pooled analyses) in trials
How often severe oral mucositis occurs.
Moderate certaintyResults and what it means
Why it was measured
To see whether glutamine prevents severe mouth sores.
Statistical vs. clinical meaning
Moderate-quality evidence by the reviewers' own rating.
Safety implication
Ask the cancer team.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | Reduced incidence of severe oral mucositis (no numbers in the abstract) | People with cancer having treatment | Glutamine (form and route not stated) |
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 4
- Very sick hospital patients: one large trial found more deaths. In a 2013 trial of 1,223 adults with multiple organ failure on ventilators, deaths at 28 days were 32.4% with glutamine and 27.2% without (adjusted OR 1.28, borderline P=0.05). Deaths in hospital and at 6 months were significantly higher with glutamine. Glutamine in this setting is only for hospital teams to decide. Randomised trial 3 8
- Diabetic kidney disease: possible kidney harm. A 2019 review says glutamine can cause glomerulosclerosis (scarring of the kidney's filters) and raise serum creatinine in the setting of diabetic nephropathy. In healthy athletes, short-term and 2-week use was linked to no significant adverse effects. People with kidney disease should ask a doctor before using glutamine. Review 2
- The prescription sickle cell product has its own side effects. In the 48-week trial, low-grade nausea, non-cardiac chest pain, fatigue and muscle or bone pain were more common with glutamine than with placebo. It was used under medical care. Randomised trial 6
- In healthy adults, no clear pattern of harm was found. A 2008 risk assessment found no consistent pattern of harm from glutamine in healthy adults. It could not set a usual upper limit. Using another method, the authors found strong evidence of no adverse effects up to 14 g a day (their Observed Safe Level) and said data above that were not enough to judge long-term safety. This is the authors' figure, not a rule from a regulator and not advice to take glutamine. Review 7
Side effects 4
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Nausea, non-cardiac chest pain, fatigue, muscle or bone pain Prescription-grade product given under medical care; the abstract does not give rates. | More common than with placebo in the sickle cell trial (230 people); rates not in the abstract. | Mild to moderate (low-grade nausea per the abstract) Not stated in the sources read. | Randomised trial 6 |
| Higher death rate in organ failure Very sick patients given glutamine by vein and by feeding tube; not a pill-taking setting. | 32.4% vs 27.2% at 28 days in one trial. | Serious Not applicable | Randomised trial 3 |
| Raised creatinine and kidney scarring in diabetic kidney disease Reported for people with diabetic nephropathy only. | Not stated. | Potentially serious Not stated in the sources read. | Review 2 |
| Few side effects in healthy people The trials are short (up to 8 weeks) and small, so rare harms may be missed. | Adverse events were low and similar to placebo in the IBS trial; the 2008 review found no systematic pattern in healthy adults. | Mild or none reported Not applicable | Randomised trial and review 12 7 |
Liver
No liver injury from glutamine was found in the sources read. A liver-safety reference (LiverTox) was blocked, so it was not read. No source read covers glutamine in liver disease or cirrhosis.
How often. No frequency was found.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Glutamine supports liver health.
Medicines and supplements 2
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Hydroxyurea (sickle cell medicine) prescription | Not studied as an interaction. About two thirds of trial participants stayed on hydroxyurea while taking glutamine. | The abstract reports benefit with or without hydroxyurea and does not describe any interaction harm. | Clinical trial Low certainty 6 | Ask the sickle cell team. |
| Medicines and other supplements in general general | No interaction studies for oral glutamine were found in the sources read. | Unknown. Absence of reports is not proof of safety. | None found Not enough evidence | Ask a pharmacist, especially if you take several medicines. |
Who should check first 6
| Situation | Advice | Evidence |
|---|---|---|
| Diabetic kidney disease or other kidney disease | A 2019 review reports kidney scarring and raised creatinine with glutamine in diabetic nephropathy. Ask a doctor before using any glutamine product. | Review 2 |
| Critical illness with organ failure | One large trial found more deaths with glutamine. Hospital teams decide on any use; it is not for self-treatment. | Randomised trial 3 |
| Pregnancy and breastfeeding | No source read described glutamine use in pregnancy or breastfeeding, so nothing can be said about safety. Ask a doctor or pharmacist before any supplement. | No evidence read |
| Children | The sickle cell trial included children from age 5 under medical care, and premature babies in hospital were studied with no benefit found. No source read covers glutamine powders for healthy children. Ask a paediatrician. | Randomised trial and systematic review 6 4 |
| Liver disease | No source read covers glutamine in liver disease. Ask a doctor. | No evidence read |
| Allergy | No allergy reports for glutamine were found in the sources read. | No evidence read |
Overdose, product quality and regulators
Summary. No clear pattern of toxicity was found in healthy adults in the trials reviewed. The main warnings are for very sick patients and for diabetic kidney disease.
Animal. Not reviewed.
Human doses studied. Amounts appear in the studies table only.
High dose or long term signals. A 2008 review found no consistent harm and set an Observed Safe Level of 14 g a day for healthy adults, saying higher amounts lacked enough data for long-term safety. A 2019 review found no significant harm after short bursts of 20 to 30 g or 2 weeks of higher amounts in healthy athletes.
Overdose response. No overdose information was found in the sources read. If someone feels very unwell after taking a supplement, seek medical help.
Genotoxicity. Not researched.
Contamination and label accuracy of glutamine products were not researched for this page.
Prescription product versus supplements. The sickle cell trial used pharmaceutical-grade L-glutamine. No source read tested the quality of over-the-counter glutamine products. 6
| Body | Action | Date |
|---|---|---|
| MedlinePlus (US National Library of Medicine) (United States) | Lists glutamine as a nonessential amino acid and also as a conditionally essential amino acid, meaning it is usually not needed from food except in times of illness and stress. source | 2026-10-26 |
When to get medical help
- Passing much less urine, new swelling of the legs or face, or sudden tiredness in someone with kidney disease or diabetes who started glutamine.
- A person in hospital or very ill who is given glutamine and gets worse: tell the care team.
- Severe chest pain, trouble breathing or a sickle cell pain crisis: seek emergency help.
- A severe allergic reaction (swelling of the face or throat, trouble breathing): call emergency services.
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
What is glutamine?
Do healthy people need glutamine supplements?
Does glutamine help sickle cell disease?
Is glutamine used in hospitals?
Does glutamine help with IBS or gut health?
One trial of 106 adults with diarrhoea-type IBS after an infection found large improvements over 8 weeks. It needs repeating. No reliable trial in healthy people was read for gut healing claims.
Does glutamine build muscle?
A 2019 review rated the evidence for glutamine on muscle mass and strength as weak or scarce. Creatine and protein had stronger evidence.
Does glutamine help mouth sores from cancer treatment?
A 2023 umbrella review found glutamine, honey and propolis can lower severe mouth sores, with moderate-quality evidence. Ask the cancer team before using any supplement.
Is glutamine safe for the kidneys?
In healthy athletes, short-term and 2-week use showed no significant harm. A 2019 review says it can cause kidney scarring and raise creatinine in diabetic kidney disease, so those people should ask a doctor.
Are there side effects?
Is glutamine safe in pregnancy or for children?
No source read covers glutamine powders in pregnancy or breastfeeding. A trial in premature babies found no benefit. Ask a doctor or pharmacist.
Does glutamine interact with medicines?
No interaction studies for oral glutamine were found in the sources read, which does not prove safety. In the sickle cell trial many people also took hydroxyurea. Ask a pharmacist.
Does glutamine help premature babies?
A Cochrane review of 12 trials with 2,877 premature babies found no effect on deaths, infection or bowel emergencies.
Explore by health goal
Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-26
- Last substantive update
- 2026-10-26
- How we research
- We started from our existing glutamine summary, read MedlinePlus, and re-read PubMed abstracts for the trials and reviews cited. Only abstracts were read for studies. The NIH Office of Dietary Supplements and FDA pages could not be read and are marked unverified.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown. The sickle cell trial was funded by the product's maker.
Sources 13
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Amiri Khosroshahi R, Talebi S, Zeraattalab-Motlagh S, Imani H et al.. Nutritional interventions for the prevention and treatment of cancer therapy-induced oral mucositis: an umbrella review of systematic reviews and meta-analyses.. Nutr Rev. 2023. PMID 36763701. DOI 10.1093/nutrit/nuac105. (abstract)
- Davani-Davari D, Karimzadeh I, Sagheb MM, Khalili H. The Renal Safety of L-Carnitine, L-Arginine, and Glutamine in Athletes and Bodybuilders.. J Ren Nutr. 2019. PMID 30341034. DOI 10.1053/j.jrn.2018.08.014. (abstract)
- Heyland D, Muscedere J, Wischmeyer PE, Cook D et al.. A randomized trial of glutamine and antioxidants in critically ill patients.. N Engl J Med. 2013. PMID 23594003. DOI 10.1056/NEJMoa1212722. (abstract)
- Moe-Byrne T, Brown JV, McGuire W. Glutamine supplementation to prevent morbidity and mortality in preterm infants.. Cochrane Database Syst Rev. 2016. PMID 27089158. DOI 10.1002/14651858.CD001457.pub6. (abstract)
- Morris CR, Hamilton-Reeves J, Martindale RG, Sarav M et al.. Acquired Amino Acid Deficiencies: A Focus on Arginine and Glutamine.. Nutr Clin Pract. 2017. PMID 28388380. DOI 10.1177/0884533617691250. (abstract)
- Niihara Y, Miller ST, Kanter J, Lanzkron S et al.. A Phase 3 Trial of l-Glutamine in Sickle Cell Disease.. N Engl J Med. 2018. PMID 30021096. DOI 10.1056/NEJMoa1715971. (abstract)
- Shao A, Hathcock JN. Risk assessment for the amino acids taurine, L-glutamine and L-arginine.. Regul Toxicol Pharmacol. 2008. PMID 18325648. DOI 10.1016/j.yrtph.2008.01.004. (abstract)
- Tao KM, Li XQ, Yang LQ, Yu WF et al.. Glutamine supplementation for critically ill adults.. Cochrane Database Syst Rev. 2014. PMID 25199493. DOI 10.1002/14651858.CD010050.pub2. (abstract)
- Valenzuela PL, Morales JS, Emanuele E, Pareja-Galeano H. Supplements with purported effects on muscle mass and strength.. Eur J Nutr. 2019. PMID 30604177. DOI 10.1007/s00394-018-1882-z. (abstract)
- Wales PW, Nasr A, de Silva N, Yamada J. Human growth hormone and glutamine for patients with short bowel syndrome.. Cochrane Database Syst Rev. 2010. PMID 20556765. DOI 10.1002/14651858.CD006321.pub2. (abstract)
- Wang J, Lu H. Benefit-risk of voxelotor, crizanlizumab, and l-glutamine in sickle cell disease: A systematic review.. Am J Med Sci. 2026. PMID 42628795. DOI 10.1016/j.amjms.2026.08.010. (abstract)
- Zhou Q, Verne ML, Fields JZ et al.. Randomised placebo-controlled trial of dietary glutamine supplements for postinfectious irritable bowel syndrome.. Gut. 2019. PMID 30108163. DOI 10.1136/gutjnl-2017-315136. (abstract)
- . MedlinePlus Medical Encyclopedia: Amino acids. . . (full-text)
Where to buy
Check the label first. Whatever you buy, look for these:
- The amount of the active ingredient per serving, not just the front-label claim
- A third-party testing mark (USP, NSF or ConsumerLab)
- Other ingredients and allergens
- Ask a pharmacist about interactions with your medicines
Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.
Support our free guides: as an Amazon Associate we earn from qualifying purchases. Full disclosure.
