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Dietary supplement

Perfect L-Glutamine Ingredients & Drug Interactions

by Nature's Best

Perfect L-Glutamine label
See full label image
Powder Category: Other Combinations
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 Perfect 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

Perfect L-Glutamine is a dietary supplement by Nature's Best with 2 active ingredients. 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 Perfect L-Glutamine by Nature's Best

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

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HelloPharmacist Scorecard of Perfect L-Glutamine by Nature's Best

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 Jul 11, 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 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This powder has two active ingredients. L-Glutamine is an amino acid your body makes naturally — it's involved in muscle recovery, immune function, and gut health, and plays a role in nitrogen balance.

The product also contains Lysophosphatidyl Choline enriched Lecithin, a form of lecithin (a fat-like substance found in eggs and soybeans) that's sometimes used to support cellular function.

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 support.
  • We looked for evidence on: Athletic performance, Exercise-induced muscle damage, Postoperative recovery, Wound healing, Critical illness (trauma), Muscle strength — and 2 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.

L-Glutamine is rated Effective for sickle cell disease and Possibly Effective for HIV/AIDS-related wasting, postoperative recovery, and critical illness from trauma. Lecithin, the second ingredient, doesn't have strong evidence behind it — it's rated Likely Ineffective for Alzheimer disease, and the evidence is insufficient to rate it for cognitive decline, fatty liver from total parenteral nutrition (TPN), anxiety, or bipolar disorder.

The evidence, ingredient by ingredient Glutamine Lecithin

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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Both ingredients are generally well tolerated. L-Glutamine commonly causes digestive upset — belching, bloating, constipation, diarrhea, flatulence, nausea, and vomiting — especially at higher doses (10–30 grams daily).

Headache and dizziness have been reported. In rare cases, people with bipolar disorder taking high glutamine doses (up to 4 grams daily) developed mania or hypomania.

If you have kidney or liver disease, use glutamine only under a doctor's supervision. Lecithin can cause abdominal pain, diarrhea, fullness, and nausea, and may trigger allergic skin reactions if you're allergic to eggs or soy.

Both are rated Likely Safe in pregnancy and lactation, though the label advises not using supplemental glutamine while breastfeeding unless your doctor recommends it.

Side effects, ingredient by ingredient Glutamine Lecithin

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 2 matched ingredients 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.

Check with your pharmacist if you take anticonvulsant medications (seizure drugs) — glutamine may theoretically reduce their effectiveness, though this hasn't been reported in humans. If you have bipolar disorder, be aware that high-dose glutamine has rarely triggered mania in some people.

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.

This product is worth considering if you're recovering from surgery, dealing with sickle cell disease, or managing severe illness — that's where the evidence for L-Glutamine is strongest. If you take anticonvulsants or have bipolar disorder, kidney disease, or liver disease, talk to your pharmacist or doctor first.

Digestive side effects are common, especially at higher doses.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Apr 22, 2016.

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 Perfect L-Glutamine, straight from the product label.

Brand Nature's Best
Barcode (UPC) 089094020989
Net contents 10.5 oz.; 300 Gram(s)
Market status On market
Date entered into DSLD Apr 22, 2016
DSLD ID 58822
Product type Other Combinations
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Perfect L-Glutamine by Nature's Best, 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 Gram(s)
Maximum serving Sizes:
5 Gram(s)
Servings per container
60
UPC/BARCODE
089094020989
IngredientAmount% DV
L-Glutamine4.6 Gram(s)--
Lysophosphatidyl Choline enriched Lecithin400 mg--

Other ingredients: Lysophosphatidyl Choline enriched Lecithin

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 Statements

PERFECT

All Nature’s Best products are manufactured from the highest quality raw materials, under strict supervision in accordance with Good Manufacturing Practices. Extensive quality control procedures ensure the proper purity, dissolution and potency. Satisfaction Guaranteed, or your money promptly refunded. Nature’s Best products are specially packaged to protect nutrients from the effects of moisture, light and air.

Formula

Nature’s Best Perfect L-Glutamine powder is formulated with your health in mind.

PLUS LYSOPHOSPHATIDYL CHOLINE

Storage

Keep tightly closed in a dry place, do not expose to excessive heat.

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.

FDA Statement of Identity

AMINO ACID DIETARY SUPPLEMENT

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement mix 1 rounded teaspoonful (5g) with your favorite beverage, 1 to 2 times daily 1 hour before a workout.

Precautions

This product is produced in a facility with soy, dairy, egg and wheat ingredients, peanuts and tree nuts.

KEEP OUT OF REACH OF CHILDREN.

Formulation

This product is gluten-free.

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

See for yourself

Perfect L-Glutamine by Nature's Best label

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

Perfect 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 Perfect L-Glutamine by Nature's Best

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size5 Gram(s) Dosage formPowder Servings per container60 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

L-Glutamine

Interacts with
50 drugs
4.6 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

Lysophosphatidyl Choline enriched Lecithin

No known
interactions
400 mg per serving

Lecithin is a natural fatty substance found in foods and made by the body that is widely used as a supplement and food emulsifier. Evidence supporting...

Lysophosphatidyl Choline enriched Lecithin monograph & interactions

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

Interaction report

Perfect L-Glutamine by Nature's Best Drug Interactions

Want to check YOUR meds against Perfect 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 Perfect L-Glutamine interact with 50 drugs. Click any drug to see the details.

1 of the 2 ingredients in Perfect 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 Perfect 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 Perfect L-Glutamine, from the product label.

Nature's Best

See all Nature's Best products
Name
Nature's Best, Inc.
Street Address
195 Engineers Road
City
Hauppauge
State
NY
ZipCode
11788
Web Address
naturesbest.com
Pharmacist Counseling Corner

Perfect L-Glutamine by Nature's Best: Common Questions

Does Perfect L-Glutamine by Nature's Best interact with any medications?
Yes. Based on its ingredients, Perfect 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?
Perfect L-Glutamine contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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 with muscle recovery after a workout?
The evidence is strongest for glutamine in postoperative recovery and critical illness — those are medical settings. We don't have data showing it works specifically for exercise recovery in healthy people.
What are the most common side effects?
Digestive issues: belching, bloating, constipation, diarrhea, flatulence, nausea, and vomiting. Headache and dizziness have also been reported. These tend to happen more at higher doses (10–30 grams daily).
Is it safe to take while pregnant or breastfeeding?
Both ingredients are rated Likely Safe in pregnancy. For breastfeeding, the label advises not using supplemental glutamine unless your doctor recommends it, even though formal safety data is limited.
What is the lecithin in this product for?
Lecithin is sometimes used to support cellular function and is occasionally used to help with clogged milk ducts while breastfeeding, but the evidence for most other uses is weak or absent.
Can I take this if I have kidney or liver problems?
No — if you have kidney or liver disease, use this product only under medical supervision. Talk to your doctor first.

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

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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.

Perfect L-Glutamine label
Go deeper

The Full Monographs Behind Perfect 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 → Herb & supplement monograph

Lecithin

Lecithin is a natural fatty substance found in foods and made by the body that is widely used as a supplement and food emulsifier. Evidence supporting most of its health claims is limited, t...

Read the full Lecithin monograph →
Sources

Sources & How We Checked

Perfect 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 20 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 →

Lecithin 9 references
  1. Buchman AL, Dubin M, Jenden D, et al. Lecithin increases plasma free choline and decreases hepatic steatosis in long-term total parenteral nutrition patients. Gastroenterology 1992;102:1363-70.
  2. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  3. Chatellier G, Lacomblez L. Tacrine (tetrahydroaminoacridine; THA) and lecithin in senile dementia of the Alzheimer type: a multicentre trial. Groupe Francais d'Etude de la Tetrahydroaminoacridine. BMJ 1990;300:495-9.
  4. Gelenberg AJ, Dorer DJ, Wojcik JD, et al. A crossover study of lecithin treatment of tardive dyskinesia. J Clin Psychiatry 1990;51:149-53.
  5. Little A, Levy R, Chuaqui-Kidd P, Hand D. A double-blind, placebo controlled trial of high-dose lecithin in Alzheimer's disease. J Neurol Neurosurg Psychiatry 1985;48:736-42. PubMed
  6. Palm M, Moneret-Vautrin DA, Kanny G, et al. Food allergy to egg and soy lecithins. Allergy 1999;54:1116-7. PubMed
  7. Drachman DA, Glosser G, Fleming P, et al. Memory decline in the aged: treatment with lecithin and physostigmine. Neurology 1982;32:944-50. PubMed
  8. Gelenberg, A. J., Doller-Wojcik, J. C., and Growdon, J. H. Choline and lecithin in the treatment of tardive dyskinesia: preliminary results from a pilot study. Am J Psychiatry 1979;136(6):772-776. PubMed
  9. Electronic Code of Federal Regulations. Title 21, Chapter 1, Subchapter B, Part 184: Direct food substances affirmed as Generally Recognized as Safe. Subpart B - listing of specific substances affirmed as GRAS. Sec. 184.1400 Lecithin. Available at: https:

See these in context on the Lecithin 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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