supplementNot FDA-approvedOTC supplementThe cited randomized trial found no benefit and a signal toward harm from high-dose glutamine in critically ill ICU patients; this does not describe healthy-adult oral supplement use
GlutamineBenefits, Dosage & Interactions
Glutamine is the most abundant free amino acid in the human body. While it is considered a non-essential amino acid because the body can produce it, it becomes conditionally essential during times of stress, such as intense exercise, injury, or illness.
Researched by DoseRoutine R&D TeamReviewed for accuracy by Nicholas Alexander, RSELast updated
Evidence: Moderate — One published human randomized trial; results not yet replicated.
Evidence strengthModerate · 3/4
PreclinicalStrong human evidence
One published human randomized trial; results not yet replicated.
Plasma half-life
Not applicable
Default unit
g
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
- Reported amounts
- The cited randomized trial used enteral and parenteral glutamine (roughly 0.35 g/kg/day enteral plus 0.5 g/kg/day parenteral) in critically ill patients with multi-organ failure and found no benefit, with a signal toward increased mortality[1]
- Route studied
- Enteral and parenteral in the cited trial; oral powder is the common consumer form[1]
- Frequency
- Daily in the cited trial[1]
- Cycle length
- Up to 28 days in the cited trial[1]
- Half-life
- Not established by this source[1]
- Storage
- Room temperature, sealed[1]
Reported for Glutamine in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Glutamine entry is written from. Each number matches an inline marker above.
- [1]A randomized trial of glutamine and antioxidants in critically ill patientsHeyland D, Muscedere J, Wischmeyer PE, et al. · The New England Journal of Medicine · 2013 · Peer-reviewed · PMID 23594003
How to track Glutamine doses
Tracking Glutamine well takes four fields and a habit. Here is what to record so the log is still useful in three months.
- 1
Add the dose and unit
Log Glutamine with its dose in g so totals stay comparable over time — including days when you split the dose or skip it.
- 2
Set the time of day and food rule
Pick the time you actually take it. Reminders fire at that time and can export to your calendar.
- 3
Check it against the rest of the stack
Run Glutamine through the interaction checker against everything else in the routine — supplements, peptides, hormones and prescriptions — before it becomes a daily habit.
- 4
Log adherence, not intentions
Mark each dose taken, skipped or delayed as it happens. Weeks of honest logs are what make an adherence rate or a trend line meaningful; retrospective guessing is not.
- 5
Review against outcomes
Review Glutamine alongside your logged metrics and any relevant blood work every few weeks before changing the dose, so the change is a response to data rather than to a good or bad day.
What to log each time
- Dose in g
- Time of day
- Taken / skipped / delayed
- Any side effects or notable changes
References & Evidence
Sources on this page that document Glutamine dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Glutamine studied for?
What is Glutamine?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Glutamine is the most abundant free amino acid in the human body. While it is considered a non-essential amino acid because the body can produce it, it becomes conditionally essential during times of stress, such as intense exercise, injury, or illness. In these situations, the body's demand for glutamine may exceed its production capacity, necessitating intake from diet or supplements. Glutamine plays a crucial role in various physiological processes, including immune function, gut health, and muscle metabolism. It serves as a primary fuel source for rapidly dividing cells, such as those lining the intestines and immune cells. Additionally, it is involved in nitrogen transport, ammonia detoxification, and as a precursor for other amino acids and nucleotides (PubChem).
What does the research say about Glutamine?
Tap a section to expand.
Glutamine's mechanisms of action are diverse and impact several bodily systems.
1. **Fuel for rapidly dividing cells:** Glutamine is a preferred metabolic fuel for enterocytes (cells lining the gut) and lymphocytes (immune cells). This means it is vital for maintaining the integrity of the intestinal barrier and for supporting a robust immune response (NIH ODS). During catabolic states, such as severe illness or intense physical stress, the demand for glutamine by these cells increases significantly.
2. **Nitrogen transport and ammonia detoxification:** Glutamine plays a key role in nitrogen metabolism. It serves as a non-toxic carrier of ammonia (a waste product) in the bloodstream, transporting it to the kidneys for excretion and to the liver for conversion into urea. This process is essential for maintaining acid-base balance and preventing ammonia toxicity (PubChem).
3. **Precursor for glutathione synthesis:** Glutamine is a precursor to glutathione, one of the body's most powerful endogenous antioxidants. Glutathione helps protect cells from oxidative damage caused by free radicals. This role is particularly relevant during strenuous exercise or in disease states where oxidative stress is elevated (NIH ODS).
4. **Muscle protein synthesis and breakdown:** While often associated with muscle building, glutamine's direct anabolic effects are not as pronounced as other amino acids like leucine. However, it plays a role in supporting muscle health indirectly. During intense exercise, glutamine stores in muscle can be depleted, potentially contributing to muscle fatigue and impaired recovery. Supplementation aims to restore these levels. It may also help regulate muscle protein synthesis and breakdown, though the exact mechanisms are still being researched (Cochrane, DrugBank).
5. **Immune system modulation:** By fueling immune cells, glutamine supports their proliferation and function. Studies suggest it can enhance lymphocyte activation and cytokine production, especially in individuals facing physiological stress (NIH ODS).
Source for this section: Sources for How does Glutamine work?: Jumps to this entry in the sources and references list at the end of the page.
Glutamine supplementation is most frequently explored for its potential benefits in specific situations:
* **Intestinal Health:** In individuals undergoing critical illness, chemotherapy, or experiencing inflammatory bowel conditions, glutamine may help maintain the integrity of the intestinal barrier, reduce bacterial translocation, and promote gut healing (NIH ODS, Cochrane). It is a vital fuel for enterocytes. Some research suggests it can help alleviate symptoms of irritable bowel syndrome (IBS) in some individuals, particularly those with diarrhea-predominant IBS, but more robust evidence is needed. (MedlinePlus).
* **Immune Function:** During periods of intense physical stress (e.g., endurance exercise, surgery, severe burns) or illness, glutamine reserves can be depleted, potentially leading to a compromised immune system. Supplementing with glutamine may help support immune cell function and reduce the incidence of infections in these populations (NIH ODS, Cochrane).
* **Exercise Recovery:** Athletes, especially those engaged in high-intensity or endurance training, may experience a temporary drop in blood glutamine levels post-exercise. Replenishing glutamine stores is hypothesized to aid in muscle recovery, reduce muscle soreness, and support immune function, thereby enhancing performance adaptation. However, the ergogenic benefits for strength or muscle growth in healthy athletes are not consistently demonstrated across all studies (Cochrane, DrugBank).
* **Wound Healing:** Due to its role in cell proliferation and immune function, glutamine has been investigated for its potential to improve wound healing, particularly in burn patients or after surgery. It may contribute to faster tissue repair and reduced complication rates (NIH ODS).
While glutamine is promoted for a range of uses, scientific evidence for its efficacy varies significantly depending on the specific condition and population (NIH ODS).
Evidence for glutamine's efficacy is substantial in certain clinical contexts, but less consistent for general athletic performance or healthy populations.
* **Clinical Populations (Critical Illness, Trauma, Surgery):** A significant body of research, including numerous randomized controlled trials and meta-analyses, supports the use of glutamine in critically ill patients, those recovering from surgery, or individuals with severe burns. Cochrane reviews and studies cited by the NIH Office of Dietary Supplements (ODS) indicate that glutamine supplementation may reduce mortality, hospital length of stay, and infection rates in these vulnerable populations by improving gut integrity and immune function.
* **Inflammatory Bowel Disease (IBD):** Some research suggests glutamine may be beneficial in managing symptoms and improving intestinal permeability in conditions like Crohn's disease and ulcerative colitis. However, evidence is not universally strong, and its role is often as an adjunct therapy. (MedlinePlus).
* **Irritable Bowel Syndrome (IBS):** Preliminary studies suggest glutamine supplementation may improve symptoms in some individuals with diarrhea-predominant IBS, particularly post-infection. More extensive research is needed to confirm these findings and establish definitive guidelines (MedlinePlus).
* **Exercise and Athletic Performance:** The evidence regarding glutamine's direct benefits for muscle growth, strength, or enhanced athletic performance in healthy athletes is mixed. While some studies suggest it can aid in reducing muscle soreness and improving recovery by supporting immune function and glycogen resynthesis post-exercise, many meta-analyses conclude that it does not consistently lead to significant ergogenic effects on muscle mass or strength beyond what a well-balanced diet provides (Cochrane, DrugBank). It is more consistently shown to help mitigate exercise-induced immune suppression.
* **Glutathione Production:** Research consistently shows that glutamine is a critical precursor for glutathione synthesis, an important antioxidant. This mechanism underpins some of its observed benefits in conditions involving oxidative stress (NIH ODS).
Overall, the strongest evidence for glutamine's clinical utility lies in supporting compromised gastrointestinal and immune systems during catabolic stress, rather than as a primary anabolic agent for healthy individuals. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Glutamine is generally well-tolerated when taken orally at typical supplemental doses. Mild side effects reported include:
* **Digestive Upset:** Nausea, vomiting, stomach pain, gas, or constipation can occur, particularly with higher doses.
* **Headache:** Some individuals have reported headaches.
* **Skin Rash:** Rarely, mild skin rashes may be observed.
* **Muscle Pain:** In some cases, muscle and joint pain have been noted, though less commonly.
Most reported side effects are transient and resolve upon discontinuation or dose reduction. Serious adverse effects are rare but can occur, especially in individuals with pre-existing conditions. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
While glutamine is generally safe for most healthy individuals, certain warnings and precautions apply:
* **Kidney or Liver Disease:** Individuals with severe liver disease (e.g., cirrhosis) or kidney disease should use glutamine with caution and under medical supervision. The body processes glutamine in these organs, and impaired function could lead to ammonia accumulation or other complications.
* **Allergies:** People with known allergies to glutamine or its derivatives should avoid supplementation.
* **Psychiatric Conditions:** Some anecdotal reports suggest glutamine might exacerbate symptoms in individuals with certain psychiatric disorders, though robust evidence is lacking. Caution is advised.
* **Reye's Syndrome:** There is a theoretical concern that glutamine might contribute to Reye's syndrome in children, especially if they have a history of viral infections. Individuals with Reye's syndrome or conditions predisposing them to elevated ammonia levels should avoid glutamine. Always consult a pediatrician before giving supplements to children.
* **Pregnancy and Breastfeeding:** There is insufficient reliable information about the safety of glutamine use during pregnancy or breastfeeding. It is best to avoid use unless specifically advised by a healthcare professional.
Always consult a healthcare provider before starting any new supplement, especially if you have pre-existing medical conditions or are taking other medications. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Glutamine should be avoided or used with extreme caution in individuals with the following conditions:
* **Severe Liver Disease (e.g., Cirrhosis):** Individuals with severe liver impairment may have difficulty metabolizing glutamine, potentially leading to dangerous ammonia accumulation in the blood (hyperammonemia). This can exacerbate hepatic encephalopathy.
* **Severe Kidney Disease:** As glutamine is excreted via the kidneys, impaired kidney function could lead to its accumulation and potential complications.
* **History of Reye's Syndrome:** Individuals with a history of Reye's syndrome or conditions that predispose them to high ammonia levels (e.g., certain urea cycle disorders) should not use glutamine due to the risk of exacerbating ammonia toxicity.
* **Monosodium Glutamate (MSG) Sensitivity:** While glutamine is not MSG, some individuals sensitive to MSG (a salt of glutamic acid) report similar reactions to glutamine. If you have a known sensitivity to MSG, exercise caution or avoid glutamine.
* **Seizure Disorders:** There are theoretical concerns that glutamine, as a precursor to glutamate (an excitatory neurotransmitter), might affect seizure thresholds in susceptible individuals. Individuals with epilepsy or other seizure disorders should consult their clinician before considering glutamine supplementation.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
While glutamine is generally considered safe and has few significant drug interactions, specific cautions should be observed:
* **Chemotherapy Agents:** There is some conflicting evidence regarding glutamine's interaction with certain chemotherapy drugs, particularly methotrexate and 5-fluorouracil. Some studies suggest it might help reduce side effects like mucositis, while others raise concerns about potential interference with drug efficacy. Patients undergoing chemotherapy should *not* use glutamine without explicit medical supervision from their oncologist. (MedlinePlus).
* **Lactulose:** Lactulose is a laxative often used in liver disease to reduce ammonia levels. Because glutamine is involved in ammonia metabolism and removal, there's a theoretical concern that very high doses of glutamine might interfere with lactulose's action or exacerbate ammonia in compromised liver states. This interaction is not well studied, but caution is advised in individuals with liver disease.
* **Supplements that affect ammonia levels:** Any supplement or medication that significantly alters the body's ammonia balance should be discussed with a clinician if considering glutamine, especially in the context of liver or kidney impairment.
Always inform your healthcare provider about all medications, supplements, and herbal products you are taking to prevent potential interactions. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
The typical timing for glutamine supplementation can vary based on the desired outcome:
* **For Exercise Recovery:** Many athletes prefer to take glutamine immediately post-workout to help replenish muscle glutamine stores and support recovery. Some also take it before or during prolonged exercise. Split doses throughout the day (e.g., morning and evening) are also common. Whether taken with or without food, the absorption is generally good.
* **For Gut Health/Immune Support:** Doses are often spread throughout the day to maintain consistent levels, typically between meals or with meals. For clinical applications, dosage and timing are user-directed and must be set by a licensed clinician.
Glutamine has a relatively short half-life of approximately 1 hour, meaning it is quickly metabolized. As such, frequent dosing, or sustained-release formulations, might be considered in some clinical contexts. The body's natural production and dietary intake also contribute to overall glutamine levels. For general supplementation, there isn't a universally agreed-upon 'best' time, and flexibility is often acceptable. User-directed dosing must be set by a licensed clinician. For OTC supplement use, follow product label instructions.
Source for this section: Sources for When should you take Glutamine?: Jumps to this entry in the sources and references list at the end of the page.
What interacts with Glutamine?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any glp1 + supplement | Note | Category ruleConfidence: theoretical | GLP-1 medications slow stomach emptying, changing how/when oral supplements absorb; rapid weight loss raises the importance of protein and micronutrients.Source pending | Time oral supplements when nausea is lowest; prioritize protein and micronutrients; discuss with your provider. |
| Any supplement + medication | Note | Category ruleConfidence: theoretical | Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).Source pending | Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist. |
Frequently asked questions about Glutamine
Glutamine is a supplement. What follows is drawn from peer-reviewed literature indexed on PubMed, FDA label text where a label exists, and NIH reference records.
Glutamine is commonly discussed in the context of supporting recovery, immune, and muscle. Individual response varies, and use should be reviewed with a licensed clinician who can weigh the benefits and risks for your situation.
For Glutamine, it is typically taken null. Always follow the specific dose your clinician or the product label prescribes.
Glutamine carries potential side effects and drug interactions, documented in NIH, Mayo Clinic, and FDA label sources. Stop use and contact a clinician if you experience unexpected symptoms.
Glutamine is a supplement, and interactions are possible with prescriptions, hormones, peptides and other supplements in the same routine. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Glutamine with no sign-up.
Combining a supplement like Glutamine with TRT is usually a question of labs rather than a blanket yes or no: the ester, injection interval and any aromatase inhibitor all change the answer. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Each peptide class carries its own profile against Glutamine: a healing peptide raises different questions than a GLP-1 agonist or a growth-hormone secretagogue. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
Published frequency for Glutamine varies by protocol and formulation, so the label or prescription is what sets it. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
The effect of a missed dose of Glutamine depends on the protocol and formulation you are on. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Glutamine the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Which studies looked at Glutamine?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Glutamine reliance in cell metabolism(opens PubMed in a new tab)Exp Mol Med · 2020 · PMID 32943735 · https://pubmed.ncbi.nlm.nih.gov/32943735/
- 2.Targeting glutamine metabolism as a therapeutic strategy for cancer(opens PubMed in a new tab)Exp Mol Med · 2023 · PMID 37009798 · https://pubmed.ncbi.nlm.nih.gov/37009798/
- 3.A systematic review and meta-analysis of clinical trials on the effects of glutamine supplementation on gut permeability in adults(opens PubMed in a new tab)Amino Acids · 2024 · PMID 39397201 · https://pubmed.ncbi.nlm.nih.gov/39397201/
- 4.Glutamine and cancer: metabolism, immune microenvironment, and therapeutic targets(opens PubMed in a new tab)Cell Commun Signal · 2025 · PMID 39856712 · https://pubmed.ncbi.nlm.nih.gov/39856712/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 75855(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/75855
Verify at
Publisher search links for Glutamine. These are places to check the information — they are not citations, so they are not numbered.
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- MedlinePlus(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed labeling archive(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Glutamine?
Plain-text summary, safe to quote verbatim:
Glutamine is the most abundant free amino acid in the human body. While it is considered a non-essential amino acid because the body can produce it, it becomes conditionally essential during times of stress, such as intense exercise, injury, or illness.
Source: DoseRoutine — https://doseroutine.com/library/glutamine
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Glutamine — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/glutamine
What compounds are similar to Glutamine?
Others in the supplement category or studied for the same goals.
Which goals is Glutamine used for?
Other compounds studied for the same benefits as Glutamine.
Continue exploring
See every compound DoseRoutine catalogs for these goals.