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 is an amino acid — one of your body's building blocks — that plays a role in immune function, gut health, and muscle recovery.

Jerusalem Artichoke root extract is included, though we have no detailed breakdown of its active compounds on file. The capsule also contains several inactive ingredients (hypromellose, cellulose, magnesium stearate, and silica), which are binders and fillers that hold the formula 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, postoperative recovery, and critical illness from trauma.

These ratings reflect what the clinical evidence shows — solid proof for sickle cell, and some promise for the others, though more research would help confirm those uses. We have no effectiveness data on file for the Jerusalem Artichoke 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 generally well tolerated in healthy adults. The most common side effects from oral doses are belching, bloating, constipation, diarrhea, flatulence, stomach pain, headache, nausea, and vomiting — especially at higher doses (10–30 grams daily).

A small number of people have reported dizziness or headache. Two patients with bipolar disorder reported mania or hypomania after taking glutamine supplements, so if you have bipolar disorder, check with your doctor first.

People with kidney or liver disease should use this only under medical supervision. There isn't enough safety data to recommend it during breastfeeding unless your doctor advises it.

L-Glutamine is rated Likely Safe in pregnancy, so if you're pregnant, it's reasonable to discuss it with your healthcare provider.

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, talk with your doctor or pharmacist before starting this product — glutamine might theoretically reduce their effectiveness, though it hasn't been documented in patients yet. We could not check the Jerusalem Artichoke extract against medications, so mention this product to your pharmacist when reviewing your full medication list.

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 may help with sickle cell disease and might support muscle and gut health during recovery from illness or surgery, though the evidence is strongest for sickle cell. If you take seizure medication, you'll want to check with your doctor or pharmacist before starting.

People with kidney or liver problems should only use it under medical supervision.

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 Feb 23, 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 FOS + L-Glutamine, straight from the product label.

Brand Genestra Brands
Barcode (UPC) 88319610430
Net contents 60 Vegetable Capsule(s)
Market status On market
Date entered into DSLD Feb 23, 2016
DSLD ID 56191
Product type Botanical With Nutrients
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Dairy 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 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
88319610430
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 five capsules three times daily, or as recommended by your healthcare practitioner.

Precautions

Risk Information: If you are pregnant or breastfeeding, do not use.

Quality Assurance: Safety-sealed for your protection and for product freshness. Do not use if outer seal is missing or broken.

Formulation

Guaranteed to contain no added wheat, starch, yeast, gluten, corn, soy, sodium, sugar, artificial colors or flavoring, antimicrobial preservatives, dairy or animal products.

Ideal for vegans.

The capsules are made from 100% pure vegetable sources, free of preservatives and additives.

Storage

Store in a cool, dry place.

FDA Statement of Identity

HERBAL AND AMINO ACID SUPPLEMENT

Seals/Symbols

Seroyal

General

422

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.
Will this help my gut health?
L-Glutamine plays a role in gut health and is used in clinical settings to support recovery after surgery and critical illness. The evidence is solid for sickle cell disease and some people use it for postoperative recovery, but we don't have specific evidence on file for general gut health support — talk with your doctor about whether it's right for your situation.
What are the most common side effects?
Most people tolerate it well, but you might notice belching, bloating, constipation, diarrhea, stomach pain, nausea, or headache, especially if you're taking higher doses. These usually ease if you reduce the dose.
Is it safe if I'm pregnant?
L-Glutamine is rated Likely Safe in pregnancy, so it's reasonable to ask your doctor about it. There isn't reliable safety data for the Jerusalem Artichoke extract during pregnancy, so mention this product to your healthcare provider before taking it.
Can I take this if I have kidney or liver disease?
If you have kidney or liver disease, use this only under medical supervision. Your doctor needs to know about it and monitor you.
What's Jerusalem Artichoke root extract for?
We don't have detailed information on file about what Jerusalem Artichoke root extract does in this formula, so ask your pharmacist or check the brand's website for more details on that ingredient's intended role.

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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