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Dietary supplement

Glutamine 1000 Caps Ingredients & Drug Interactions

by ON Optimum Nutrition

Glutamine 1000 Caps label
See full label image
Capsule 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 Glutamine 1000 Caps 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

Glutamine 1000 Caps is a dietary supplement by ON Optimum Nutrition 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 Glutamine 1000 Caps by ON Optimum Nutrition

Ask about any prescription or over-the-counter medication and we check it for interactions with Glutamine 1000 Caps by ON Optimum Nutrition — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Glutamine 1000 Caps by ON Optimum Nutrition

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 6, 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 your body makes naturally and also gets from protein-rich foods. The capsule itself is made from gelatin and magnesium stearate, which are inactive ingredients used to form and stabilize the supplement.

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 protein development and recovery.
  • We looked for evidence on: Exercise-induced muscle damage, Postoperative recovery, Athletic performance, Wound healing, muscle atrophy, sports nutrition.
  • 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 Wound healing, Exercise-induced muscle damage.

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

Evidence for other uses hasn't been established in the data we hold.

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 when taken by mouth. Most side effects are gastrointestinal—belching, bloating, constipation, diarrhea, flatulence, nausea, vomiting, and stomach pain are the most common.

Headache and musculoskeletal pain have also been reported. A small number of trial participants experienced dizziness, which resolved when the dose was lowered.

Two people with bipolar disorder reported mania or hypomania symptoms while taking glutamine up to 4 grams daily; glutamine is metabolized to glutamate, which might have neurological effects in people with certain brain conditions. If you have kidney or liver disease, use glutamine only under medical supervision.

Safety data in pregnancy is limited, though glutamine is rated likely safe; talk with your doctor before using it while pregnant. Data for breastfeeding is insufficient—avoid supplement doses while nursing 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 medications (seizure drugs), double-check with your doctor or pharmacist before starting this supplement. Glutamine theoretically might reduce how well these drugs work, though this hasn't been confirmed in patients yet.

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.

Glutamine may help with sickle cell disease and possibly with surgical recovery or wasting from serious illness. If you take seizure medications, check with your doctor or pharmacist before starting this product.

It's generally well tolerated, but gastrointestinal side effects are common, and it warrants caution if you have kidney or liver problems.

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 25, 2013.

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 Glutamine 1000 Caps, straight from the product label.

Brand ON Optimum Nutrition
Barcode (UPC) 748927025859
Net contents 240 Capsule(s)
Market status On market
Date entered into DSLD Sep 25, 2013
DSLD ID 25920
Product type Amino Acid/protein
Supplement form Capsule
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 Glutamine 1000 Caps by ON Optimum Nutrition, 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 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
240
UPC/BARCODE
748927025859
IngredientAmount% DV
L-Glutamine1 Gram(s)--

Other ingredients: Gelatin, Magnesium Stearate

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.
FDA Statement of Identity

DIETARY SUPPLEMENT

Seals/Symbols

ON(TM)

Suggested/Recommended/Usage/Directions

SUGGESTED USE: Consume 1-2 capsules between meals, 30-45 minutes before workouts and/or immediately after workouts.

Formula

1,000 MG L- GLUTAMINE

Our Glutamine 1000 Caps are formulated for rapid disintegration and provide 1,000 mg of pure L-Glutamine per capsule so they deliver a quick, powerful dose each and every time.

Brand IP Statement(s)

(C)2007 OPTIMUM NUTRITION, INC

THE BIGGER PICTURE(TM)

General

07-135-585

General Statements

THE BIGGER PICTURE OF GLUTAMINE Glutamine is the most abundant amino acid in the body and plays an important role in muscle protein development. During prolonged periods of intense exercise glutamine levels may be depleted faster than the body can replenish them, which limits protein synthesis and encourages muscle breakdown.

Precautions

KEEP OUT OF REACH OF CHILDREN. CHECK WITH A QUALIFIED HEALTHCARE PROFESSIONAL BEFORE USING THIS PRODUCT IF YOU ARE UNDER 18 YEARS OF AGE, PREGNANT OR NURSING A BABY OR IF YOU HAVE ANY KNOWN OR SUSPECTED MEDICAL CONDITION(S) AND/OR ARE TAKING ANY PRESCRIPTION OR OTC MEDICATION(S).

CHECK WITH A QUALIFIED HEALTHCARE PROFESSIONAL BEFORE USING THIS PRODUCT IF YOU ARE UNDER 18 YEARS OF AGE, PREGNANT OR NURSING A BABY OR IF YOU HAVE ANY KNOWN OR SUSPECTED MEDICAL CONDITION(S) AND/OR ARE TAKING ANY PRESCRIPTION OR OTC MEDICATION(S).

Storage

STORE IN A COOL, DRY PLACE.

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

Glutamine 1000 Caps by ON Optimum Nutrition label

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

Glutamine 1000 Caps 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 Glutamine 1000 Caps by ON Optimum Nutrition

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container240 Amounts shown are per serving.

L-Glutamine

Interacts with
50 drugs
1 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 monograph & interactions

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

Interaction report

Glutamine 1000 Caps by ON Optimum Nutrition Drug Interactions

Want to check YOUR meds against Glutamine 1000 Caps?

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 Glutamine 1000 Caps interact with 50 drugs. Click any drug to see the details.

1 of the 1 ingredient in Glutamine 1000 Caps 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 Glutamine 1000 Caps 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 Glutamine 1000 Caps, from the product label.

ON Optimum Nutrition

See all ON Optimum Nutrition products
Name
ON(TM)
City
Sunrise
State
FL
ZipCode
33325
Pharmacist Counseling Corner

Glutamine 1000 Caps by ON Optimum Nutrition: Common Questions

Does Glutamine 1000 Caps by ON Optimum Nutrition interact with any medications?
Yes. Based on its ingredients, Glutamine 1000 Caps 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?
Glutamine 1000 Caps 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 me recover faster after surgery?
Glutamine is possibly effective for recovery after surgery based on available evidence. It's not a guarantee, and results vary. Ask your doctor whether it makes sense for your situation.
What side effects should I expect?
Most side effects are stomach-related: bloating, gas, nausea, diarrhea, or constipation. Headache and muscle pain have also been reported. Start with a lower dose to see how your body responds, and reduce it if you feel dizzy.
Can I take this if I'm pregnant?
Glutamine is rated likely safe in pregnancy, but safety data is limited. Talk with your doctor before using it while pregnant to make sure it's right for you.
Is this supplement FDA-approved?
Supplements are not FDA-approved the way drugs are. Our information comes from clinical trials and monographs on glutamine, not from FDA oversight of this specific product.
What is L-glutamine, and where does it come from?
L-glutamine is an amino acid—a building block of protein—that your body naturally makes and you get from foods like meat, eggs, and dairy. This supplement provides a concentrated dose of it.

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

Not sure if Glutamine 1000 Caps 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.

Glutamine 1000 Caps label
Go deeper

The Full Monographs Behind Glutamine 1000 Caps’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

Glutamine 1000 Caps'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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