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Dietary supplement

L-Glutamine Powder Ingredients & Drug Interactions

by GNC Pro Performance

L-Glutamine Powder 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 Powder 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 Powder is a dietary supplement by GNC Pro Performance 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 Powder by GNC Pro Performance

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

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HelloPharmacist Scorecard of L-Glutamine Powder by GNC Pro Performance

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 (a building block of protein) that your body uses for immune function, gut health, and muscle recovery. L-glutamine is an amino acid your body makes on its own, but supplemental doses are sometimes used to support recovery from illness or physical stress.

Does it work?

Strong 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
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: muscle recovery and immune system support.
  • We looked for evidence on: Exercise-induced muscle damage, Postoperative recovery, Wound healing, Oral mucositis, Critical illness (trauma), Sickle cell disease — and 3 related terms.
  • The strongest evidence on file: Glutamine is rated "Effective" for Sickle cell disease (Natural Medicines).
  • Also on file: Glutamine is rated "Possibly Effective" for Critical illness (trauma), Postoperative recovery.
  • Also on file: Glutamine is rated "Insufficient Reliable Evidence To Rate" for Oral mucositis, Wound healing, Exercise-induced muscle damage.

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 supporting these uses comes from clinical research, though for wasting and postoperative recovery the data is still being built.

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 when taken orally. The most common side effects are gastrointestinal—belching, bloating, constipation, flatulence, nausea, vomiting, diarrhea, and stomach pain—as well as headache and musculoskeletal pain.

At high doses (10–30 grams daily), GI side effects are more likely. Dizziness and headache have been reported; one patient who had dizziness on a high dose improved when the dose was cut in half.

Two patients with bipolar disorder reported mood changes (mania or hypomania) while taking glutamine, so caution applies if you have a mood disorder. People with kidney or liver disease should only use this supplement under a doctor's supervision.

Not enough safety data exists for pregnancy, so only use it if your doctor recommends it. Breastfeeding safety data is limited; avoid supplement doses unless a clinician advises otherwise.

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.

Check your anticonvulsant (seizure) medications before taking this product. Glutamine may theoretically reduce how well these drugs work, though this hasn't been confirmed in humans yet.

If you take any seizure medication, use the search tool on this page to look up your specific drug.

Check your own medication Run your meds through the checker above

The bottom line

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

L-glutamine may be worth considering if you have sickle cell disease or are recovering from surgery or critical illness—talk that over with your doctor. If you take seizure medication, you must check with your doctor or pharmacist before starting this product.

People with kidney or liver disease, and anyone with bipolar disorder, should discuss it with their healthcare provider first.

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 Dec 23, 2011.

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 Powder, straight from the product label.

Brand GNC Pro Performance
Barcode (UPC) 048107052225
Net contents 8 oz.; 227.2 g
Market status On market
Date entered into DSLD Dec 23, 2011
DSLD ID 2711
Product type Amino Acid/protein
Supplement form Powder
Dietary claims / uses Nutrient, 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 Powder by GNC Pro Performance, 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:
5 Gram(s)
Maximum serving Sizes:
5 Gram(s)
Servings per container
45
UPC/BARCODE
048107052225
IngredientAmount% DV
L-Glutamine5 g--

Other ingredients: None

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.
Suggested/Recommended/Usage/Directions

DIRECTIONS:As a dietary supplement, take one heaping teaspoon (5g) post exercise in 8 fl. oz. of water or fruit juice and another 5g serving 2 hours later.

Precautions

KEEP OUT OF REACH OF CHILDREN.

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.

Storage

Store in a cool, dry place.

Formula

5 GRAMS OF L-GLUTAMINE PER SERVING

General

CODE 762339 AGG

General Statements

EASY-TO-MIX POWDER

Glutamine, one of the most abundant amino acids found in skeletal muscles, serves as fuel for the immune system, provides an anti-catabolic effect and is involved in protein synthesis.+ Prolonged high-intensity exercise has shown to decrease glutamine levels, which may result in glutamine deficiency.

Lot No./Best By:

Made in the USA

Notice: Significant product settling may occur.

Supplementing with Pro Performance(R) L-Glutamine Powder may help in maintaining glutamine stores. Each serving supplies 5 grams of L-Glutamine powder and blends easily with any beverage or sports drink.

UNFLAVORED

FDA Statement of Identity

DIETARY SUPPLEMENT

FREE-FORM AMINO ACID

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

See for yourself

L-Glutamine Powder by GNC Pro Performance label

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

L-Glutamine Powder 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 Powder by GNC Pro Performance

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

Serving size5 Gram(s) Dosage formPowder Servings per container45 Amounts shown are per serving.

L-Glutamine

Interacts with
50 drugs
5 g 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

Other (inactive) ingredients: None. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Glutamine Powder by GNC Pro Performance Drug Interactions

Want to check YOUR meds against L-Glutamine Powder?

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 Powder interact with 50 drugs. Click any drug to see the details.

1 of the 1 ingredient in L-Glutamine Powder 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 Powder 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 Powder, from the product label.

GNC Pro Performance

See all GNC Pro Performance products
Phone Number
1-888-462-2548
Pharmacist Counseling Corner

L-Glutamine Powder by GNC Pro Performance: Common Questions

Does L-Glutamine Powder by GNC Pro Performance interact with any medications?
Yes. Based on its ingredients, L-Glutamine Powder 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 Powder 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.
Is L-glutamine safe to take while pregnant?
L-glutamine is rated likely safe in pregnancy, so it's not off-limits. But there isn't a lot of safety data, so talk it over with your doctor before you start—they know your situation best.
Can I take this if I'm breastfeeding?
Safety data for supplement doses while breastfeeding is limited. We don't have enough information to say it's safe, so check with your doctor or lactation consultant before you take it.
What are the most common side effects?
Stomach issues are the most common—bloating, gas, nausea, constipation, or diarrhea. You might also get a headache or muscle soreness. These tend to happen more often at higher doses.
Is this product effective for muscle recovery?
The data we hold rates L-glutamine effective for sickle cell disease and possibly effective for recovery after surgery and critical illness. Evidence for general athletic or muscle recovery isn't established in our data.
What is L-glutamine and why would I take it?
L-glutamine is an amino acid—a building block your body uses for immunity, gut function, and muscle repair. Your body makes it on its own, but supplemental doses are used to support recovery from serious illness, surgery, or trauma.
If I have kidney or liver disease, can I take this?
People with kidney or liver disease should only use L-glutamine under medical supervision. Talk with your doctor before starting, since your ability to process it may be affected.

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

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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 Powder label
Go deeper

The Full Monographs Behind L-Glutamine Powder’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 Powder'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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