Interactions on record — worth a quick check against your medications. Based on 1 of 2 ingredients. Check your meds →
Dietary supplement

FOS + L-Glutamine Ingredients & Drug Interactions

by Genestra Brands

FOS + L-Glutamine label
See full label image
Capsule Category: Botanical With Nutrients
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 FOS + 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

FOS + L-Glutamine is a dietary supplement by Genestra Brands 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 FOS + L-Glutamine by Genestra Brands

Ask about any prescription or over-the-counter medication and we check it for interactions with FOS + L-Glutamine by Genestra Brands — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of FOS + L-Glutamine by Genestra Brands

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 30, 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 product contains 2 active ingredients: L-glutamine and Jerusalem Artichoke root extract. L-glutamine is an amino acid your body uses for gut health and immune function.

The Jerusalem Artichoke root is a plant extract, though we hold no detailed information on its role in this formulation. The capsule also contains inactive ingredients — hypromellose, cellulose, magnesium stearate, and silica — which are fillers and binders that help hold the supplement together.

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

This product doesn't appear to be marketed for a specific use, so we graded Glutamine's overall clinical evidence instead.

Strong

Strong clinical evidence supports Glutamine for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Sickle cell disease — rated "Effective" (Natural Medicines).
  • On file: HIV/AIDS-related wasting — rated "Possibly Effective" (Natural Medicines).
  • On file: Critical illness (trauma) — rated "Possibly Effective" (Natural Medicines).
  • On file: Postoperative recovery — rated "Possibly Effective" (Natural Medicines).
  • On file: Pancreatitis — rated "Possibly Effective" (Natural Medicines).

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

We hold no effectiveness data for the Jerusalem Artichoke root extract in this product.

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 rated likely safe in pregnancy and lactation. In general, it's well tolerated in healthy adults.

The most common side effects are digestive — belching, bloating, constipation, flatulence, nausea, and diarrhea, especially at higher doses. A few people have reported dizziness or headache, and rare cases of mood changes (mania or hypomania) have been noted in people with bipolar disorder.

If you have kidney or liver disease, use L-glutamine only under medical supervision. There isn't enough safety data to recommend supplement doses while breastfeeding unless your doctor advises 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 anticonvulsants (seizure medications), check with your doctor or pharmacist before using this product — glutamine might theoretically reduce how well these drugs work. We hold no interaction data for the Jerusalem Artichoke root extract.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

L-glutamine in this product is effective for sickle cell disease and possibly effective for recovery from surgery or trauma and HIV-related weight loss. If you take seizure medication, check with your doctor or pharmacist first — glutamine might theoretically interfere with how those drugs work.

Otherwise, it's generally well tolerated, though digestive side effects are common at higher doses.

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

Assessment coverage: 1 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated May 28, 2019.

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 FOS + L-Glutamine, straight from the product label.

Brand Genestra Brands
Barcode (UPC) 883196104307
Net contents 60 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD May 28, 2019
DSLD ID 203087
Product type Botanical With Nutrients
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 FOS + L-Glutamine by Genestra Brands, 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 Capsule(s)
Maximum serving Sizes:
5 Capsule(s)
Servings per container
12
UPC/BARCODE
883196104307
IngredientAmount% DV
Total Carbohydrates1 Gram(s)1%
L-Glutamine1500 mg--
Jerusalem Artichoke (Helianthus tuberosus) root std. extract925 mg--

Other ingredients: Hypromellose, Cellulose, Magnesium Stearate, Silica

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

Recommended dose: Take 5 capsules 3 times daily, or as recommended by your health professional.

Precautions

Warning: If you are pregnant or lactating, do not use. If you have any health condition or are taking any medication, consult your health professional before use.

Keep out of the reach of children.

Use only if safety seal is intact.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

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.

General Statements

Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity. Scan to learn about our quality excellence

Supports gastrointestinal health

General

V2 422-60U

FDA Statement of Identity

Dietary Supplement

Formula

FOS + L-Glutamine

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

See for yourself

FOS + L-Glutamine by Genestra Brands label

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

FOS + 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 FOS + L-Glutamine by Genestra Brands

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

Serving size5 Capsule(s) Dosage formCapsule Servings per container12 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
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

Jerusalem Artichoke (Helianthus tuberosus) root std. extract

925 mg per serving Form: Total Fructans

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

Interaction report

FOS + L-Glutamine by Genestra Brands Drug Interactions

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

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

Genestra Brands

Name
Seroyal USA
City
Pittsburgh
State
PA
ZipCode
15275
Phone Number
1-888-737-6925
Web Address
seroyal.com
Pharmacist Counseling Corner

FOS + L-Glutamine by Genestra Brands: Common Questions

Does FOS + L-Glutamine by Genestra Brands interact with any medications?
Yes. Based on its ingredients, FOS + 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?
FOS + 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.
Is L-glutamine safe during pregnancy and breastfeeding?
L-glutamine is rated likely safe in pregnancy. While breastfeeding, there isn't enough safety data on supplement doses, so talk with your doctor or pharmacist about whether it's right for you.
What are the most common side effects?
Digestive upset is most common — belching, bloating, constipation, gas, nausea, and diarrhea, especially at higher doses. Headache and dizziness are less common. If you notice mood changes (mania or hypomania), stop and talk with your doctor.
Will this help my gut health?
L-glutamine is used by your body for gut and immune function, but we hold no specific effectiveness data in our facts for general gut health. Talk with your doctor about whether it's appropriate for your needs.
Can I take this if I have kidney or liver disease?
Only under medical supervision. If you have kidney or liver disease, check with your doctor or pharmacist before using this product.
What's the Jerusalem Artichoke root for?
We hold no detailed information on its role in this formulation. Your pharmacist can tell you more about why the manufacturer included it.

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

Not sure if FOS + L-Glutamine 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.

FOS + L-Glutamine label
Go deeper

The Full Monographs Behind FOS + 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 →
Sources

Sources & How We Checked

FOS + 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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