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Dietary supplement

Glutamine Powder Unflavored Ingredients & Drug Interactions

by ON Optimum Nutrition

Glutamine Powder 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 Glutamine Powder 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

Glutamine Powder Unflavored 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 Powder Unflavored by ON Optimum Nutrition

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Glutamine Powder Unflavored 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 just one active ingredient: L-glutamine, an amino acid your body naturally makes and uses for muscle repair, immune function, and gut health. It's offered as an unflavored powder you can mix into drinks or food.

There are no other 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 protein development and recovery.
  • We looked for evidence on: Athletic performance, Exercise-induced muscle damage, Postoperative recovery, Wound healing, 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 "Possibly Ineffective" for Athletic performance.

The evidence supports glutamine for sickle cell disease—that's rated Effective. For HIV/AIDS-related wasting, postoperative recovery, and critical illness from trauma, the evidence is Possibly Effective, meaning the research suggests a benefit but isn't yet complete enough to call it proven.

If you're considering this for one of those uses, talk it over with your doctor about whether it makes sense for your situation.

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. The most common side effects are gastrointestinal—belching, bloating, constipation, diarrhea, flatulence, nausea, and vomiting.

Headache and musculoskeletal pain have also been reported. High doses (10–30 grams daily) used in clinical trials for sickle cell disease caused more GI upset.

Rare cases of dizziness and neurological effects (mania or hypomania) have occurred, especially in people with bipolar disorder; one person's dizziness resolved when the dose was cut in half. If you have kidney or liver disease, you should take this only under medical supervision.

During pregnancy, glutamine is rated Likely Safe. There isn't enough safety data for supplemental doses while breastfeeding, so talk with your doctor or pharmacist before using it in that situation.

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 (seizure) medications, check with your doctor or pharmacist before starting this supplement. Glutamine may theoretically work against how these drugs control seizures.

No other medication interactions are documented in the data we have.

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 with wasting from HIV/AIDS, recovery after surgery, or critical illness—but the evidence is strongest for sickle cell disease. If you take anticonvulsant (seizure) medications, check with your doctor or pharmacist first.

Most people tolerate it well, though GI upset is common, especially at higher doses. Talk it over with your own healthcare provider to make sure it fits your needs.

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 Jul 21, 2022.

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 Powder Unflavored, straight from the product label.

Brand ON Optimum Nutrition
Barcode (UPC) 748927022810
Net contents 10.6 Ounce(s); 300 Gram(s)
Market status On market
Date entered into DSLD Jul 21, 2022
DSLD ID 270344
Product type Amino Acid/protein
Supplement form Powder
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating)
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 Powder Unflavored 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:
5.15 Gram(s)
Maximum serving Sizes:
5.15 Gram(s)
Servings per container
58
UPC/BARCODE
748927022810
IngredientAmount% DV
L-Glutamine5 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.
Formula

The True Strength 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 can be depleted which may limit protein synthesis. Our Glutamine Powder is a simple way to supplement your diet with this amino acid. Just one teaspoon of Glutamine Powder provides more glutamine than 4 jumbo eggs, 4 oz. of lean beef, 3/4 cup of soybeans, or a 4 oz. chicken breast. Because it's unflavored and instantized for easy mixing, you can add the powder into fruit juice, protein shakes or your favorite weight gain formula.

5 g glutamine supplement

Precautions

Warning: Consult your physician before using this product if you are taking any medications or are under a physician's care for a medical condition.

Not for use by those under the age of 18 or women that are pregnant, trying to get pregnant, or nursing.

Not for use by those under the age of 18 or women that are pregnant, trying to get pregnant, or nursing.

Storage

Store in a cool, dry place.

General Statements

Contents sold by weight not volume.

True strength www.optimumnutrition.com

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: Mix one heaping teaspoon of Glutamine Powder with 8 oz. of water or your favorite beverage daily as part of a healthy diet and exercise program. Intended for use in healthy adults as part of a healthy, balance diet and exercise program.

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.

Seals/Symbols

Manufactured in the USA This product contains ingredients of international and domestic origin.

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

See for yourself

Glutamine Powder Unflavored by ON Optimum Nutrition label

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

Glutamine Powder 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 Glutamine Powder Unflavored by ON Optimum Nutrition

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

Serving size5.15 Gram(s) Dosage formPowder Servings per container58 Amounts shown are per serving.

L-Glutamine

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 monograph & interactions

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

Interaction report

Glutamine Powder Unflavored by ON Optimum Nutrition Drug Interactions

Want to check YOUR meds against Glutamine Powder 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 50

Individual Drug Interactions

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

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

ON Optimum Nutrition

See all ON Optimum Nutrition products
Name
Optimum Nutrition, Inc.
Street Address
975 Meridian Lake Dr.
City
Aurora
State
IL
ZipCode
60504
Phone Number
1-800-705-5226
Web Address
Truestrength.com
Pharmacist Counseling Corner

Glutamine Powder Unflavored by ON Optimum Nutrition: Common Questions

Does Glutamine Powder Unflavored by ON Optimum Nutrition interact with any medications?
Yes. Based on its ingredients, Glutamine Powder 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?
Glutamine Powder 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 should I expect?
Digestive upset is the most common issue—belching, bloating, constipation, diarrhea, nausea, and vomiting. Headache and muscle pain have also been reported. These are usually mild, but high doses (10–30 grams daily) cause more GI distress. If you notice side effects, try a lower dose and talk with your pharmacist.
Is this safe during pregnancy?
Yes, glutamine is rated Likely Safe in pregnancy. You can take it without special concern, but as always, let your doctor know you're using it.
Is it safe while breastfeeding?
There isn't enough safety data to say for certain. Talk with your doctor or pharmacist before using supplemental glutamine while breastfeeding—they can help you decide based on your individual situation.
What does glutamine actually do?
It's an amino acid your body uses for muscle repair, immune function, and gut health. The evidence is strongest for helping people with sickle cell disease. For other conditions like surgery recovery or wasting from HIV/AIDS, it may help, but the evidence isn't as clear.
How much should I take?
The facts we have cover doses from 5 to 30 grams daily, depending on the condition. Your doctor can recommend the right amount for your needs. Start at the lower end if you're new to it, especially if you're concerned about digestive upset.
Can I use this if I have kidney or liver disease?
Not without medical supervision. Talk with your doctor first—they can determine whether it's safe for your kidneys or liver and monitor you if you decide to take it.

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

Not sure if Glutamine Powder Unflavored is safe with your meds?

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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.

Glutamine Powder Unflavored label
Go deeper

The Full Monographs Behind Glutamine Powder 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

Glutamine Powder 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

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