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Dietary supplement

L-Glutamine Ingredients & Drug Interactions

by GNC Men's

L-Glutamine label
See full label image
Other (e.g. Tea Bag) 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 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 is a dietary supplement by GNC Men's 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 by GNC Men's

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

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HelloPharmacist Scorecard of L-Glutamine by GNC Men's

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.

GNC Men's L-Glutamine contains one active ingredient: L-glutamine, an amino acid your body makes and uses. The product also includes cellulose as an inactive ingredient (a binder).

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

This product doesn't appear to be marketed for a specific use, so we graded Glutamine's overall clinical evidence instead.

Strong

Strong clinical evidence supports Glutamine for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Sickle cell disease — rated "Effective" (Natural Medicines).
  • On file: HIV/AIDS-related wasting — rated "Possibly Effective" (Natural Medicines).
  • On file: Critical illness (trauma) — rated "Possibly Effective" (Natural Medicines).
  • On file: Postoperative recovery — rated "Possibly Effective" (Natural Medicines).
  • On file: Pancreatitis — rated "Possibly Effective" (Natural Medicines).

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

The evidence for those other uses is solid but not yet conclusive.

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. However, if you have kidney or liver disease, you should only use it under your doctor's supervision.

The most common side effects from oral doses are belching, bloating, constipation, diarrhea, flatulence, nausea, vomiting, headache, and gastrointestinal pain — especially at higher doses (10–30 grams daily). Rare cases of dizziness, mania, or hypomania have been reported, and people with neurological conditions should be cautious.

There isn't enough safety data to know whether it's safe at supplement doses during pregnancy or breastfeeding, so talk with your doctor or pharmacist before using it if you're pregnant, planning pregnancy, or 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 medications (drugs to prevent seizures), check your exact medication names with the search tool on this page before starting L-glutamine. The interaction is Moderate severity and has been suggested in theory, though not yet reported in humans.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

L-glutamine may help with sickle cell disease and may support recovery from surgery or serious illness. If you take anticonvulsant (seizure) medication, check your specific drugs before starting — your doctor or pharmacist can advise whether it's right for you.

Expect possible digestive side effects, especially at higher doses, and avoid supplement doses in pregnancy or while breastfeeding unless your doctor recommends otherwise.

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 Feb 25, 2019.

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, straight from the product label.

Brand GNC Men's
Net contents 30 Vitapaks
Market status On market
Date entered into DSLD Feb 25, 2019
DSLD ID 191086
Product type Amino Acid/protein
Supplement form Other (e.g. Tea Bag)
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult Male (18-50 Years), Gluten Free, Dairy 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 L-Glutamine by GNC Men's, 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:
1 White Caplet(s)
Maximum serving Sizes:
1 White Caplet(s)
IngredientAmount% DV
L-Glutamine1000 mg--

Other ingredients: Cellulose

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

CODE 336311 AJG

Precautions

Directions: As a dietary supplement, take the contents of one packet daily with food.

Warning: Consult your physician prior to using this product if you are pregnant, nursing, taking medication, or have a medical condition.

Discontinue use two weeks prior to surgery.

Keep out of reach of children.

General Statements

Potencies verified by GNC procedure #5014. Conforms to USP <2091> for weight. Meets USP <2040> disintegration.

Actual size

GNC quality commitment GNC, the leader in the development and manufacture of dietary supplements, is committed to producing the highest quality products available. This commitment begins with quality designed supplement formulation. Every raw material that goes into a GNC supplement is guaranteed as to quality and potency. Each product is dated and the shipped immediately to our stores, so you can be sure you are purchasing the freshest supplements available. At GNC, we extend out quality commitment to you by offering our money-back guarantee.

GNC guarantee Use any GNC supplement for as little as 10 days. If you are not 100% completely satisfied, return the unused portion of the product with proof of purchase to your GNC store for a complete refund of your purchase price. No questions asked.

Made in the USA

Multivitamin support Increases energy levels Supports muscle and protein synthesis Boosts nitric oxide

Dr. Frank J. Costa, M.D., an internationally acclaimed urological surgeon and men's health expert, is part of the GNC Medical Advisory Board. One of "America's Top Physicians," Dr. Costa lectures nationally and internationally on men's health topics. Dr. Costa is regularly featured in television, radio and newspaper interviews and has published articles in both professional journals and popular magazines. "Proper nutrition is essential for optimal athletic performance. I recommend the Mega Men Sport Vitapak. It provides a strategic combination of vitamins, minerals and other nutrients to fuel performance while supporting good health."

Adequate nutrition is essential for both optimal health and athletic performance. In fact, proper nutrition during training is one of the keys to success. Strenuous workouts can deplete the body of important nutrients, particularly minerals and water soluble vitamins. Exercise can also increase oxidation that, in turn, increases the production of harmful free radicals.

This complete nutritional plan provides a convenient way to achieve your daily nutritional goals. Each packet is easy to take with you to the gym, to work or when traveling.

Formulation

No artificial colors, no wheat, no gluten, no dairy, yeast free.

Storage

Store in a cool, dry place.

FDA Statement of Identity

Dietary Supplement

Formula

Performance program for active men

L-Glutamine - An important amino acid that plays a pivotal role in the nitrogen balance in the body, provides an anti-catabolic effect and is involved in protein synthesis. Prolonged high-intensity exercise has been shown to decrease glutamine levels.

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.

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

See for yourself

L-Glutamine by GNC Men's label

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

L-Glutamine 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 by GNC Men's

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

Serving size1 White Caplet(s) Dosage formOther (e.g. Tea Bag) Amounts shown are per serving.

L-Glutamine

Interacts with
50 drugs
1000 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

Other (inactive) ingredients: Cellulose. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Glutamine by GNC Men's Drug Interactions

Want to check YOUR meds against L-Glutamine?

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

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

GNC Men's

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

L-Glutamine by GNC Men's: Common Questions

Does L-Glutamine by GNC Men's interact with any medications?
Yes. Based on its ingredients, L-Glutamine 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 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 is L-glutamine and what does it do?
L-glutamine is an amino acid — a building block your body already makes and uses. In this product it's used to support recovery from illness, surgery, or wasting conditions like those seen in HIV/AIDS.
Can I take this while pregnant or breastfeeding?
There isn't enough safety data to say whether supplement doses are safe during pregnancy or breastfeeding. Talk with your doctor or pharmacist before using it if you're pregnant, trying to get pregnant, or nursing — they can give you personalized advice.
What side effects should I expect?
Most people experience digestive symptoms: belching, bloating, constipation, diarrhea, flatulence, nausea, or stomach pain. Headache is also common. Higher doses (10–30 grams daily) are more likely to cause these. Rare cases of dizziness or mood changes have been reported.
Is this product safe if I have liver or kidney disease?
If you have kidney or liver disease, you should only use L-glutamine under your doctor's supervision. Talk with them before starting.
Does this product actually work?
L-glutamine is effective for sickle cell disease. It's possibly effective for HIV/AIDS-related wasting, recovery after surgery, and critical illness — the evidence is solid but not yet definitive.

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

Not sure if L-Glutamine 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.

L-Glutamine label
Go deeper

The Full Monographs Behind L-Glutamine’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'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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