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Dietary supplement

L-Glutamine Unflavored Ingredients & Drug Interactions

by MET-Rx

L-Glutamine Unflavored label
See full label image
Powder Category: Amino Acid/protein
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking L-Glutamine Unflavored against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

L-Glutamine Unflavored is a dietary supplement by MET-Rx with 1 active ingredient. Its ingredients are commonly taken for muscle recovery and sports performance, gut health and 'leaky gut', recovery from severe illness or injury.Based on those ingredients, 50 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are L-Glutamine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against L-Glutamine Unflavored by MET-Rx

Ask about any prescription or over-the-counter medication and we check it for interactions with L-Glutamine Unflavored by MET-Rx — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of L-Glutamine Unflavored by MET-Rx

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Aug 13, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: L-glutamine, an amino acid your body makes naturally and uses for immune function, gut health, and muscle repair. The powder form delivers glutamine without added flavors or fillers — it's a straightforward single-ingredient supplement.

Glutamine is found in protein-rich foods and is especially important during times of physical stress, illness, or intense training. This supplement is meant to boost intake when food sources alone may not be enough.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: muscle recovery and post-workout support.
  • We looked for evidence on: Exercise-induced muscle damage, Athletic performance, Postoperative recovery, Critical illness (trauma), Wound healing, muscle repair — and 2 related terms.
  • The strongest evidence on file: Glutamine is rated "Possibly Effective" for Critical illness (trauma) (Natural Medicines).
  • Also on file: Glutamine is rated "Possibly Effective" for Postoperative recovery.
  • Also on file: Glutamine is rated "Possibly Ineffective" for Athletic performance.

The evidence is strongest for sickle cell disease, where glutamine is rated effective. For HIV/AIDS-related wasting, postoperative recovery, and critical illness from trauma, the evidence is promising but incomplete — these are rated possibly effective, meaning the studies suggest a benefit but more research is needed to be certain.

If you're considering glutamine for any of these uses, talk it over with your doctor to see if it fits your situation.

The evidence, ingredient by ingredient Glutamine

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Glutamine is generally well tolerated by healthy adults. The most common side effects are digestive — belching, bloating, constipation, diarrhea, flatulence, nausea, vomiting, and stomach pain.

Headache and musculoskeletal pain have also been reported. High doses (10–30 grams daily) used in clinical trials were more likely to trigger GI upset.

If you have kidney or liver disease, use glutamine only under medical supervision. There's not enough safety data in pregnancy and lactation, so avoid supplement doses unless your doctor specifically recommends them.

If you have bipolar disorder, be aware that mania and hypomania have been reported in two patients taking glutamine supplements, though this is rare.

Side effects, ingredient by ingredient Glutamine

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Glutamine.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: seizure medications.
  • For scale: 50 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take anticonvulsant medications (seizure drugs), confirm with your doctor or pharmacist before using this product — glutamine may theoretically work against how they function, though this hasn't been proven in patients yet. That's the only medication interaction documented in our data for this ingredient.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

MET-Rx L-Glutamine works best if you're dealing with sickle cell disease or recovering from surgery or critical illness, though the evidence for the latter two is still developing. If you take anticonvulsant medications, check with your doctor or pharmacist before starting — the interaction is theoretical but worth confirming.

For most healthy adults without kidney or liver problems, it's well tolerated, though digestive side effects are common at higher doses.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Nov 21, 2016.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about L-Glutamine Unflavored, straight from the product label.

Brand MET-Rx
Barcode (UPC) 786560367257
Net contents 2.2 lb; 35.28 oz.; 1000 Gram(s)
Market status On market
Date entered into DSLD Nov 21, 2016
DSLD ID 66280
Product type Amino Acid/protein
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for L-Glutamine Unflavored by MET-Rx, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
6 Gram(s)
Maximum serving Sizes:
6 Gram(s)
Servings per container
167
UPC/BARCODE
786560367257
IngredientAmount% DV
Calories25 Calorie(s)--
L-Glutamine6000 mg--

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

New look

Glutamine levels may decrease with intense training and exercise. It is important to replenish depleted glutamine levels in the body with the proper supplementation in order to effectively support your recovery after exercise.*

Contents are sold by weight. Some settling may occur.

Replenish Key Nutrient Lost During Training

Suggested/Recommended/Usage/Directions

POST WORKOUT For maximum benefits on workout days, consume two (2) servings immediately after exercise.

Directions: For adults, mix one (1) rounded scoop (6 g) into 4-8 ounces of water or your favorite beverage one to two times daily. On workout days, consume two (2) servings immediately after exercise.

Formula

MET-Rx L-Glutamine Powder is an amino acid supplement often used by active men and women, bodybuilders and athletes.

6g Glutamine Accelerates Post-Workout Recovery*

Brand IP Statement(s)

MET-Rx L-Glutamine Powder may also provide you with fuel for your workout and help support protein metabolism by being utilized as cellular fuel in the muscles.*

MET-Rx Sports Nutrition

2016

Precautions

WARNING: If you are pregnant, nursing, taking any medications or have any medical condition, consult your doctor before use.

Discontinue use and consult your doctor if any adverse reactions occur.

Not intended for use by persons under the age of 18.

KEEP OUT OF REACH OF CHILDREN.

TAMPER RESISTANT: DO NOT USE IF SEAL UNDER CAP IS BROKEN OR MISSING.

As a reminder, discuss the supplements and medications you take with your health care providers.

Storage

STORE AT ROOM TEMPERATURE AND AVOID EXCESSIVE HEAT.

FDA Disclaimer Statement

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Formulation

No Artificial Sweeteners, Flavors or Colors

FDA Statement of Identity

DIETARY SUPPLEMENT POWDER

General

36725 03C B67808 Part No. 30-41077

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

L-Glutamine Unflavored by MET-Rx label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

L-Glutamine Unflavored label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in L-Glutamine Unflavored by MET-Rx

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size6 Gram(s) Dosage formPowder Servings per container167 Amounts shown are per serving.

L-Glutamine

Interacts with
50 drugs
6000 mg per serving

Glutamine is the most abundant amino acid in the body and is usually made in your muscles. A prescription form is FDA-approved to help reduce sickle c...

L-Glutamine monograph & interactions
Interaction report

L-Glutamine Unflavored by MET-Rx Drug Interactions

Want to check YOUR meds against L-Glutamine Unflavored?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
50Drugs
50 Moderate

Ingredients driving the most interactions

L-Glutamine 50

Individual Drug Interactions

The ingredients in L-Glutamine Unflavored interact with 50 drugs. Click any drug to see the details.

1 of the 1 ingredient in L-Glutamine Unflavored interact with drugs. Each result below shows which ingredient is responsible. L-Glutamine

Each ingredient & the kinds of drugs it affects

For each ingredient in L-Glutamine Unflavored with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

L-Glutamine1 drug type · 50 drugs

Anticonvulsants

Theoretically, glutamine might antagonize the effects of anticonvulsant medications.
Glutamine is metabolized to the excitatory neurotransmitter glutamate. Glutamate might have antagonistic effects with anticonvulsant drugs. However, this interaction has not yet been reported in humans.

Likelihood Possible Evidence D
L-Glutamine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for L-Glutamine Unflavored, from the product label.

MET-Rx

See all MET-Rx products
Name
MET-Rx Nutrition, Inc.
City
Boca Raton
State
FL
ZipCode
33487
Phone Number
1-800-556-3879
Web Address
www.MET-Rx.com
Pharmacist Counseling Corner

L-Glutamine Unflavored by MET-Rx: Common Questions

Does L-Glutamine Unflavored by MET-Rx interact with any medications?
Yes. Based on its ingredients, L-Glutamine Unflavored has a known interaction with 50 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
L-Glutamine Unflavored contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Will this help with muscle recovery after workouts?
Our data shows glutamine is effective for sickle cell disease and possibly effective for postoperative recovery and recovery from critical illness or trauma. The evidence for typical muscle recovery after normal exercise isn't covered in these ratings. Talk to your doctor about whether it makes sense for your specific situation.
What's the most common side effect?
Digestive upset is most common — belching, bloating, constipation, diarrhea, flatulence, nausea, and stomach pain. These tend to be worse at higher doses. If you experience side effects, reducing your dose may help, as one reported case showed improvement when the amount was cut in half.
Is it safe to take while pregnant or breastfeeding?
Pregnancy is likely safe based on available data. For breastfeeding, there isn't enough reliable safety information, so avoid supplement doses unless your doctor recommends it. Either way, talk with your doctor or pharmacist before starting.
Can I take this if I have kidney or liver disease?
Not without medical supervision. If you have either condition, check with your doctor or pharmacist first — glutamine needs to be monitored in these situations.
Why is glutamine in this product?
Glutamine is an amino acid your body uses for immune function, gut lining health, and muscle repair. This supplement boosts your intake when you may not be getting enough from food alone, especially during illness, recovery, or intense physical stress.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if L-Glutamine Unflavored is safe with your meds?

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Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

L-Glutamine Unflavored label
Go deeper

The Full Monographs Behind L-Glutamine Unflavored’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Glutamine

Interacts with 50 drugs

Glutamine is the most abundant amino acid in the body and is usually made in your muscles. A prescription form is FDA-approved to help reduce sickle cell disease complications, but for most...

Read the full Glutamine monograph →
Sources

Sources & How We Checked

L-Glutamine Unflavored's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 11 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Glutamine 11 references
  1. Miller AL. Therapeutic considerations of L-glutamine: a review of the literature. Altern Med Rev 1999;4:239-48..
  2. Bozzetti F, Biganzoli L, Gavazzi C, et al. Glutamine supplementation in cancer patients receiving chemotherapy: a double-blind randomized study. Nutrition 1997;13:748-51.. PubMed
  3. Mebane AH. L-Glutamine and mania. Am J Psychiatry 984;141:1302-3.
  4. Meldrum BS. Glutamate as a neurotransmitter in the brain: review of physiology and pathology. J Nutr 2000;130:1007S-15S.. PubMed
  5. Garlick PJ. Assessment of the safety of glutamine and other amino acids. J Nutr 2001;131:2556S-61S.. PubMed
  6. Chapman AG. Glutamate and epilepsy. J Nutr 2000;130:1043S-5S.. PubMed
  7. Ziegler TR. Glutamine supplementation in cancer patients receiving bone marrow transplantation and high dose chemotherapy. J Nutr 2001;131:2578S-84S.. PubMed
  8. Laviano A, Molfino A, Lacaria MT, Canelli A, De Leo S, Preziosa I, Rossi Fanelli F. Glutamine supplementation favors weight loss in nondieting obese female patients. A pilot study. Eur J Clin Nutr. 2014 Nov;68(11):1264-6. PubMed
  9. Endari (l-glutamine) [package insert]. Torrance, CA: Emmaus Medical,Inc; 2017.
  10. Niihara Y, Miller ST, Kanter J, et al. A Phase 3 Trial of l-Glutamine in Sickle Cell Disease. N Engl J Med 2018;379(3):226-35. doi: 10.1056/NEJMoa1715971.
  11. Ogden HB, Child RB, Fallowfield JL, et al. Gastrointestinal Tolerance of Low, Medium and High Dose Acute Oral l-Glutamine Supplementation in Healthy Adults: A Pilot Study. Nutrients. 2020;12(10):2953. PubMed

See these in context on the Glutamine monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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