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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 16, 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 is pure L-glutamine, an amino acid your body makes naturally and uses in muscle recovery, immune function, and gut health. There are no inactive ingredients — it's the single active ingredient only.

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 fuel and protein metabolism support.
  • We looked for evidence on: Exercise-induced muscle damage, Athletic performance, Postoperative recovery, Critical illness (trauma), HIV/AIDS-related wasting, Wound healing — and 3 related terms.
  • The strongest evidence on file: Glutamine is rated "Possibly Effective" for HIV/AIDS-related wasting (Natural Medicines).
  • Also on file: Glutamine is rated "Possibly Effective" for Critical illness (trauma), Postoperative recovery.
  • Also on file: Glutamine is rated "Possibly Ineffective" for Athletic performance.

L-glutamine is rated effective for sickle cell disease. It's rated possibly effective for HIV/AIDS-related wasting, recovery after surgery, and critical illness from trauma.

The evidence base varies by condition, so talk with your doctor about whether it makes sense for what you're dealing with.

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.

L-glutamine is generally well tolerated in healthy adults. The most common side effects are digestive — belching, bloating, gas, constipation, diarrhea, nausea, and stomach pain — especially at higher doses (10–30 grams daily).

A few people have reported dizziness and headache, and rare cases of mood changes (mania or hypomania) have occurred in people with bipolar disorder taking it. If you have kidney or liver disease, use it only under your doctor's supervision.

There isn't enough safety data to recommend it during pregnancy beyond what your doctor advises, and the same goes for breastfeeding — talk with your doctor or pharmacist before taking it if you're nursing.

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 medication (seizure drugs), check with your doctor or pharmacist before starting this supplement — there's a moderate-severity theoretical concern it could reduce how well your medication works. No other medication interactions are documented in our data for the ingredients we could check.

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.

L-glutamine may help with sickle cell disease and could support recovery after surgery or serious illness, though the evidence is stronger for some uses than others. If you take anticonvulsants, check with your doctor or pharmacist first — there's a theoretical concern it could interfere.

Start with a lower dose to see how your digestive system tolerates it, and avoid high doses on your own without medical guidance.

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) 786560367295
Net contents 0.88 lb; 14.1 oz.; 400 Gram(s)
Market status On market
Date entered into DSLD Nov 21, 2016
DSLD ID 66281
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
786560367295
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.
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.

General Statements

Contents are sold by weight. Some settling may occur.

Replenish Key Nutrient Lost During Training

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.*

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.

Formula

6g Glutamine Accelerates Post-Workout Recovery*

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

Formulation

No Artificial Sweeteners, Flavors or Colors

FDA Statement of Identity

DIETARY SUPPLEMENT POWDER

Suggested/Recommended/Usage/Directions

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.

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

General

36729 05E B67808 Part No. 30-41054

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 my muscles recover faster after workouts?
L-glutamine is rated possibly effective for recovery after surgery and critical illness, but the facts on file don't establish its role in muscle recovery from regular exercise. Your doctor or a sports nutritionist can give you better guidance on that use.
What's the most common side effect?
Digestive issues — bloating, gas, constipation, diarrhea, and nausea — are the most common, especially at higher doses. Starting with a smaller amount and increasing gradually often helps.
Can I take it while I'm pregnant?
L-glutamine is rated likely safe in pregnancy, but there isn't a lot of safety data. Talk with your doctor about whether supplemental glutamine is right for you during pregnancy — they know your individual situation best.
Is it safe if I have kidney problems?
If you have kidney or liver disease, use it only under medical supervision. Don't start it on your own — check with your doctor first.
What is L-glutamine and why is it in supplements?
L-glutamine is an amino acid your body makes naturally. It's used for immune function, gut health, and muscle recovery, and the research backs it for sickle cell disease and possibly for recovery from surgery or serious illness.

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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