Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Micronized L-Glutamine Unflavored Ingredients & Drug Interactions

by GNC Pro Performance

Micronized 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 Micronized 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

Micronized L-Glutamine Unflavored 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, Micronized. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Micronized L-Glutamine Unflavored by GNC Pro Performance

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Micronized L-Glutamine Unflavored 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 20, 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, in a micronized form (finely ground particles for better absorption). L-glutamine is an amino acid—a building block your body uses for protein and for supporting muscle, immune function, and gut health, especially during recovery from illness or surgery.

There are no inactive ingredients listed.

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 support with exercise.
  • We looked for evidence on: Athletic performance, Exercise-induced muscle damage, Postoperative recovery, Wound healing, Oral mucositis, Critical illness (trauma) — and 4 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 "Possibly Ineffective" for Athletic performance.

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

Outside these uses, the evidence we hold isn't established.

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 by mouth in healthy adults. The most common side effects are gastrointestinal—belching, bloating, constipation, diarrhea, flatulence, nausea, vomiting, and stomach pain.

Headache and musculoskeletal pain have also been reported. A couple of cases of mood changes (mania and hypomania) occurred in people with bipolar disorder taking glutamine, though they're rare.

If you have kidney or liver disease, use this only under medical supervision. There isn't enough safety data to recommend supplemental doses during pregnancy or breastfeeding unless your doctor advises it—talk with your healthcare provider for personalized guidance.

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), double-check with your doctor or pharmacist before starting this product. Glutamine could theoretically reduce how well these drugs work, though it hasn't been seen in patients yet.

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 help with sickle cell disease and possibly aid recovery after surgery or serious illness. If you take seizure medications, check with your doctor or pharmacist before starting—this supplement could theoretically interfere with them.

People with kidney or liver disease should get medical supervision before using it. Have a conversation with your own healthcare provider about whether it's right for you.

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 Sep 21, 2017.

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 Micronized L-Glutamine Unflavored, straight from the product label.

Brand GNC Pro Performance
Barcode (UPC) 048107169916
Net contents 10.58 Oz(s); 300 Gram(s)
Market status On market
Date entered into DSLD Sep 21, 2017
DSLD ID 78483
Product type Amino Acid/protein
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
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 Micronized L-Glutamine Unflavored 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
60
UPC/BARCODE
048107169916
IngredientAmount% DV
L-Glutamine, Micronized5 Gram(s)--

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.
Brand IP Statement(s)

Pro Performance results

General Statements

Supplementation may help maintain glutamine levels that have been depleted as a result of intense exercise. Glutamine is involved in protein synthesis and plays a pivotal role in the body's nitrogen balance. It serves as fuel for the immue system and maintenance of proper intestinal function.

This system micronizes large molecules into small particles, which are easier to absorb, maximizing the delivery of glutamine. When used in conjunction with an exercise program.

Key amino acid for muscles Fuels the immune system

Formulation

Pro Performance quality Pro Performance L-Glutamin features our advanced micronized formula - instantized and gluten free to blend easily with your favorite beveage.

Banned substance free

Gluten free.

Precautions

Keep out of reach of children.

Storage

Store in a cool, dry place.

Seals/Symbols

Banned substance free

Gf Gluten free

Informed-Choice.org Trusted by sport Products bearing this logo have been tested for banned substance by LGC Science, Inc., a world-class anti-doping lab. Product was tested for over 145 banned substances on the 2017 World Anti-Doping Agency (WADA) Prohibited List vis LGC skip lot testing protocol #ICP0307. See gnc.com for more information.

Formula

5000 mg L-Glutamine

FDA Statement of Identity

Dietary Supplement

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.

General

CODE 386493 BSG

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, mix one scoop (5 g) twice daily in a beverage or shake. For maximum results, take one serving (5 g) post-exercise.

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

See for yourself

Micronized L-Glutamine Unflavored by GNC Pro Performance label

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

Micronized 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 Micronized L-Glutamine Unflavored 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 container60 Amounts shown are per serving.

L-Glutamine, Micronized

Interacts with
50 drugs
5 Gram(s) 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, Micronized monograph & interactions

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

Interaction report

Micronized L-Glutamine Unflavored by GNC Pro Performance Drug Interactions

Want to check YOUR meds against Micronized 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, Micronized 50

Individual Drug Interactions

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

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

Each ingredient & the kinds of drugs it affects

For each ingredient in Micronized 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-Glutamine, Micronized1 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, Micronized full monograph & interactions
The maker

Brand information

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

GNC Pro Performance

See all GNC Pro Performance products
Name
General Nutrition Corporation
City
Pittsburgh
State
PA
ZipCode
15222
Phone Number
1-888-462-2548
Web Address
gnc.com
Pharmacist Counseling Corner

Micronized L-Glutamine Unflavored by GNC Pro Performance: Common Questions

Does Micronized L-Glutamine Unflavored by GNC Pro Performance interact with any medications?
Yes. Based on its ingredients, Micronized 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?
Micronized 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.
What side effects might I notice from L-glutamine?
Stomach issues are most common—bloating, gas, constipation, diarrhea, nausea, or cramping. Headache and muscle pain have also been reported. These tend to happen at higher doses. If you notice dizziness or mood changes, reduce your dose or stop and talk to your doctor.
Is it safe to take while pregnant or breastfeeding?
During pregnancy, L-glutamine is rated likely safe. However, there isn't enough data to know if supplement doses are safe while breastfeeding, so talk with your doctor or pharmacist first before using it.
What's the difference between micronized and regular L-glutamine?
Micronized means the particles are very finely ground, which helps your body absorb it better and faster than regular powder would.
Does L-glutamine actually work for muscle recovery?
The data we have shows it's possibly effective for recovery after surgery and for critical illness from trauma. If you're using it for general muscle building or post-workout recovery outside those scenarios, the evidence we hold doesn't establish it works.
Should I be careful if I have kidney or liver problems?
Yes—if you have kidney or liver disease, use this supplement only under medical supervision. Your doctor or pharmacist can help you decide if it's appropriate for you.

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

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

Our pharmacists answer your medication & supplement questions — free.

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.

Micronized L-Glutamine Unflavored label
Go deeper

The Full Monographs Behind Micronized 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

Micronized 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

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team