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Dietary supplement

L-Glutamine Ingredients & Drug Interactions

by GNC Pro Performance

Capsule Category: Amino Acid/protein
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

L-Glutamine 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.

HelloPharmacist Scorecard of L-Glutamine 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

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. The capsule itself is made from gelatin.

L-Glutamine plays a role in immune function, gut health, and muscle recovery. Your body produces it on its own, but supplements may be used when you're recovering from surgery, dealing with severe illness, or managing certain health conditions.

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: maintain glutamine stores for exercise recovery.
  • We looked for evidence on: Exercise-induced muscle damage, Athletic performance, Postoperative recovery, Muscle protein synthesis, Training adaptation.
  • The strongest evidence on file: Glutamine is rated "Possibly Effective" for Postoperative recovery (Natural Medicines).
  • Also on file: Glutamine is rated "Possibly Ineffective" for Athletic performance.
  • Also on file: Glutamine is rated "Insufficient Reliable Evidence To Rate" for Exercise-induced muscle damage.

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 — meaning there's some evidence it may help, but more research would strengthen the case.

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. Common side effects include bloating, belching, flatulence, nausea, vomiting, diarrhea, constipation, headache, and gastrointestinal pain.

A very small number of people have reported dizziness or, in rare cases, mood changes (mania or hypomania) — one case of dizziness resolved when the dose was lowered. If you have kidney or liver disease, use L-Glutamine only under medical supervision.

During pregnancy, the safety data suggests it's likely safe, but there isn't enough reliable information for breastfeeding — talk with your doctor or pharmacist before taking it while nursing. Don't use supplemental doses unless your doctor recommends it.

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), double-check with your doctor or pharmacist before adding L-Glutamine. The interaction is theoretical and hasn't been confirmed in people, but it's worth confirming your specific medications are safe to use together.

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 possibly with recovery from surgery or critical illness. If you take seizure medication, check with your doctor or pharmacist first.

It's generally well tolerated, but can cause stomach upset in some people — side effects usually involve bloating, gas, or nausea. Talk it over with your own healthcare provider before starting, especially if you have liver or kidney disease or are breastfeeding.

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, straight from the product label.

Brand GNC Pro Performance
Barcode (UPC) 048107068233
Net contents 180 Capsule(s)
Market status On market
Date entered into DSLD Dec 23, 2011
DSLD ID 2712
Product type Amino Acid/protein
Supplement form Capsule
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 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:
2 Capsule(s)
Maximum serving Sizes:
4 Capsule(s)
Servings per container
90
UPC/BARCODE
048107068233
IngredientAmount% DV
L-Glutamine1500 mg--

Other ingredients: Gelatin

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 dietar supplement, take 2-4 capsules daily, preferably 2 capsules before exercise and 2 capsules after exercise.

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.

*This statement has 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

1500 MG PER SERVING

General Statements

Adding Pro Performance(R) L-Glutamine after intense exercise may help in maintaining glutamine stores.

Conforms to USP <2091> for weight.

L-Glutamine serves as fuel for the immune system; it may provide an anti-catabolic effedt and is involved in protein systheses.*

Made in the USA

Meets USP <2040> disintegration.

Potency verified by GNC procedure #5052.

Studies have shown that intense exercise may contribute to the depletion of glutamine in the muscles therefore resulting in a catabolic response.*

SUPPORTS MUSCLE FUNCTION DURING & AFTER EXERCISE*

General

CODE 789812 BHG

Formulation

No Sugar, No Starch, No Artificial Colors, No Artificial Flavors, Sodium Free, No Wheat, No Gluten, No Corn, No Soy, No Dairy, Yeast Free.

FDA Statement of Identity

DIETARY SUPPLEMENT

FREE-FORM AMINO ACID

See for yourself

L-Glutamine by GNC Pro Performance label

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

What’s inside

The Ingredients in L-Glutamine by GNC Pro Performance

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

Serving size2 Capsule(s) Dosage formCapsule Servings per container90 Amounts shown are per serving.

L-Glutamine

Interacts with
50 drugs
1500 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: Gelatin. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Glutamine by GNC Pro Performance 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

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
The maker

Brand information

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

GNC Pro Performance

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

L-Glutamine by GNC Pro Performance: Common Questions

Does L-Glutamine by GNC Pro Performance 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 used for?
L-Glutamine is an amino acid that may help with sickle cell disease, recovery after surgery, and wasting associated with HIV/AIDS or critical illness. It supports immune function and gut health. Talk with your doctor about whether it's appropriate for your situation.
What are the most common side effects?
The most common side effects are gastrointestinal: bloating, belching, flatulence, nausea, vomiting, diarrhea, and stomach pain. Headache and muscle pain have also been reported. Most people tolerate it well, but if stomach upset happens, it may improve at a lower dose.
Is L-Glutamine safe to take while pregnant?
The safety data rates L-Glutamine as likely safe during pregnancy. That said, talk with your doctor before starting any supplement when you're pregnant to make sure it's right for you.
Can I take L-Glutamine while breastfeeding?
There isn't enough reliable safety information for breastfeeding. The data advises against supplemental doses unless your doctor or pharmacist recommends it. Check with your clinician before taking it while nursing.
Does L-Glutamine interact with my seizure medication?
There's one documented concern: glutamine is broken down into glutamate, which might theoretically work against anticonvulsant drugs. This interaction hasn't been confirmed in people yet, but it's worth discussing with your doctor or pharmacist before you start.
What's in this product besides L-Glutamine?
The capsule is made from gelatin. There are no other active ingredients.

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

Not sure if L-Glutamine 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 label
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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