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Dietary supplement

L-Glutamine 500 mg Ingredients & Drug Interactions

by Best Naturals

Tablet Or Pill Category: Amino Acid/protein
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

L-Glutamine 500 mg is a dietary supplement by Best Naturals 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 500 mg by Best Naturals

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, a building block amino acid your body naturally makes and uses. The tablet also includes several inactive ingredients—dicalcium phosphate, cellulose, silica, vegetable magnesium stearate, stearic acid, croscarmellose sodium, and pharmaceutical glaze—which are fillers, binders, and capsule materials that don't contribute to the supplement's intended effect.

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 recovery and sports performance.
  • We looked for evidence on: Athletic performance, Exercise-induced muscle damage, Postoperative recovery, Wound healing, Critical illness (trauma), Burns — and 3 related terms.
  • The strongest evidence on file: Glutamine is rated "Possibly Effective" for Critical illness (trauma) (Natural Medicines).
  • Also on file: Glutamine is rated "Possibly Effective" for Postoperative recovery.
  • Also on file: Glutamine is rated "Possibly Ineffective" for Athletic performance, Burns.

L-glutamine is rated effective for sickle cell disease. For HIV/AIDS-related wasting, postoperative recovery, and critical illness from trauma, the evidence is considered possibly effective—meaning there's some supporting research, but it's not yet conclusive.

The data we hold doesn't show a rating for any other uses.

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 by healthy adults. The most common side effects from oral doses are gastrointestinal: belching, bloating, constipation, diarrhea, flatulence, nausea, and vomiting.

Headache and musculoskeletal pain have also been reported. A few rare cases of dizziness and mood changes (mania or hypomania) have been noted in people with bipolar disorder taking higher doses.

If you have kidney or liver disease, use this supplement only under medical supervision. Safety data isn't sufficient for supplemental doses during pregnancy or breastfeeding unless your doctor recommends it—talk with your healthcare provider about whether this is right for you in those situations.

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), verify this product with your doctor or pharmacist before starting—glutamine might theoretically reduce how well they work. No other drug interactions are documented for the ingredients we could check, but that doesn't mean none exist with your specific medications.

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 be worth considering if you have sickle cell disease or are recovering from surgery or critical illness, but the evidence for those last two uses is still developing. If you take anticonvulsant medications, check with your doctor or pharmacist before starting this supplement.

Anyone with kidney or liver disease should also get clearance from their healthcare provider first.

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 Jun 16, 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 L-Glutamine 500 mg, straight from the product label.

Brand Best Naturals
Barcode (UPC) 817716010632
Net contents 250 Tablet(s)
Market status On market
Date entered into DSLD Jun 16, 2022
DSLD ID 269810
Product type Amino Acid/protein
Supplement form Tablet Or Pill
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Sugar 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 500 mg by Best Naturals, 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 Tablet(s)
Maximum serving Sizes:
2 Tablet(s)
Servings per container
250
UPC/BARCODE
817716010632
IngredientAmount% DV
L-Glutamine500 mg--

Other ingredients: Dicalcium Phosphate, Cellulose, Silica, Vegetable Magnesium Stearate, Stearic Acid, Croscarmellose Sodium, Pharmaceutical Glaze

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

L-Glutamine is the most abundant free amino acid found in the body, comprising more than 60% of the free amino acid pool in skeletal muscle and greater than 20% of total circulating amino acids. It is involved in many metabolic processes, including the synthesis and protection of muscles tissue, the production of glycogen, and immune support during periods of immune and muscular stress. Certain research publications indicate that it may help support the following Supports muscle mass Supports the integrity of the intestinal lining

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take two (2) tablets two times daily, preferably before and after your workout, or as directed by your qualified healthcare professional. Consider taking this product in combination with Best Naturals B-6.

Precautions

Keep out of the reach of children.

Do not use if safety seal is broken or missing.

Caution: For adults only, if you are pregnant, nursing, taking any medications or have any medical condition, consult your doctor before use.

Discontinue use and consult your doctor if any adverse reactions occur.

Storage

Keep in 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.

Seals/Symbols

Made in USA

GMP Good Manufacturing Practice Product

Formulation

Premium formula

3rd party lab tested

No artificial color, flavor or sweetener, no preservatives, no sugar, no starch, no corn, no soy, no egg, no lactose, no gluten, no wheat, no yeast, no fish.

FDA Statement of Identity

Dietary Supplement

See for yourself

L-Glutamine 500 mg by Best Naturals label

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

What’s inside

The Ingredients in L-Glutamine 500 mg by Best Naturals

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

Serving size2 Tablet(s) Dosage formTablet Or Pill Servings per container250 Amounts shown are per serving.

L-Glutamine

Interacts with
50 drugs
500 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: Dicalcium Phosphate, Cellulose, Silica, Vegetable Magnesium Stearate, Stearic Acid, Croscarmellose Sodium, Pharmaceutical Glaze. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Glutamine 500 mg by Best Naturals Drug Interactions

Want to check YOUR meds against L-Glutamine 500 mg?

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 500 mg 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 500 mg, from the product label.

Best Naturals

See all Best Naturals products
Name
Best Naturals
Street Address
PO Box 394
City
Kenilworth
State
NJ
ZipCode
07033
Phone Number
1-877-659-6004
Web Address
www.shopbestnaturals.com
Pharmacist Counseling Corner

L-Glutamine 500 mg by Best Naturals: Common Questions

Does L-Glutamine 500 mg by Best Naturals interact with any medications?
Yes. Based on its ingredients, L-Glutamine 500 mg 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 500 mg 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 uses to make proteins and other compounds. Your body makes its own glutamine naturally, but this supplement provides an additional dose. It's been studied for sickle cell disease, post-surgery recovery, and helping people with HIV/AIDS wasting regain muscle.
Can I take this while I'm pregnant or breastfeeding?
Pregnancy is rated likely safe based on the data we hold. For breastfeeding, though, there isn't enough reliable safety information, so you shouldn't take supplemental doses unless your doctor specifically recommends it. Talk with your healthcare provider about what's right for your situation.
What side effects might I experience?
Most people tolerate it well. The most common side effects are digestive—bloating, constipation, diarrhea, nausea, and stomach pain. Headache has also been reported. A few rare cases of dizziness and mood changes have occurred in people taking higher doses or with bipolar disorder.
Do I need to worry about this if I have kidney or liver problems?
Yes—if you have either condition, you should only use this supplement under medical supervision. Your doctor or pharmacist can advise whether it's appropriate for you and at what dose.
Is this supplement proven to work?
It's rated effective for sickle cell disease. For HIV/AIDS wasting, post-surgery recovery, and recovery from critical illness, the evidence is possibly effective—meaning there's some research supporting it, but more work is needed to be certain.

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

Not sure if L-Glutamine 500 mg 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 500 mg label
Go deeper

The Full Monographs Behind L-Glutamine 500 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Sources

Sources & How We Checked

L-Glutamine 500 mg'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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