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Dietary supplement

Muscle Fiber Unflavored Powder Ingredients & Drug Interactions

by FINAFLEX

Muscle Fiber Unflavored Powder label
See full label image
Powder Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Muscle Fiber Unflavored Powder 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

Muscle Fiber Unflavored Powder is a dietary supplement by FINAFLEX with 4 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, 2,081 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Dietary Fiber, Vitamin D3, L-Glutamine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Muscle Fiber Unflavored Powder by FINAFLEX

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Muscle Fiber Unflavored Powder by FINAFLEX

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 27, 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 4 of its 4 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

FINAFLEX Muscle Fiber contains 4 active ingredients. L-glutamine is an amino acid your body uses during and after intense exercise and stress.

Vitamin D3 supports bone health and calcium absorption. Fructooligosaccharide is a type of soluble fiber that feeds beneficial gut bacteria.

Soluble fiber also helps with digestion and bowel regularity. The powder also contains silica as an inactive ingredient (an anti-caking agent).

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 its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients 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 ingredients' overall clinical evidence instead.
  • On file: Constipation — rated "Effective" (Black Psyllium) (Natural Medicines).
  • On file: Familial hypophosphatemia — rated "Effective" (Vitamin D) (Natural Medicines).
  • On file: Osteomalacia — rated "Effective" (Vitamin D) (Natural Medicines).
  • On file: Renal osteodystrophy — rated "Effective" (Vitamin D) (Natural Medicines).
  • On file: Rickets — rated "Effective" (Vitamin D) (Natural Medicines).

The evidence for this product's ingredients is mixed. L-glutamine is effective for sickle cell disease and possibly effective for HIV/AIDS-related wasting, recovery after surgery, and critical illness from trauma.

Vitamin D3 is effective for treating rickets, renal bone disease (a kidney-related condition), low phosphate levels, and underactive parathyroid glands. Fructooligosaccharide, however, has insufficient evidence in our data to rate its effectiveness for any condition—constipation, bone health, blood sugar control, traveler's diarrhea, and cholesterol are all areas where evidence is lacking.

The evidence, ingredient by ingredient Glutamine Black Psyllium Vitamin D Fructo-oligosaccharides (fos)

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 4 of the 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 4 of 4.
  • General safety write-ups exist for 4 of 4.
  • 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, but people with kidney or liver disease should use it only under medical supervision. Common side effects from oral use include belching, bloating, constipation, diarrhea, nausea, vomiting, headache, and stomach pain.

At very high doses, it has caused dizziness in one person (resolved at a lower dose) and mood changes in two people with bipolar disorder. The product is likely safe in pregnancy, but there isn't enough reliable safety data for supplement use while breastfeeding—talk with your doctor or pharmacist before taking it during pregnancy or nursing.

Vitamin D3 is generally safe at recommended doses, but very high doses over time can cause toxicity with symptoms like high blood calcium, bone loss, and eye inflammation. Fructooligosaccharide is generally well tolerated at food amounts but can cause gas, bloating, and stomach pain, especially at higher doses; supplement-level safety is not well studied.

There is limited safety data for FOS at supplement doses, so check with your doctor before using it at these levels.

Side effects, ingredient by ingredient Glutamine Black Psyllium Vitamin D Fructo-oligosaccharides (fos)

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?
  • 3 of the 4 matched ingredients can interact with medications — Black Psyllium, Glutamine, Vitamin D.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: seizure medications; heart-rhythm medications; lithium.
  • For scale: 2,082 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.

Before you start, check with your doctor or pharmacist if you take anticonvulsants (seizure medications), as L-glutamine may theoretically reduce their effect. If you take heart rhythm medications—verapamil, diltiazem, or digoxin—or thiazide diuretics for blood pressure, vitamin D3 can raise blood calcium and interfere with how these work.

Also double-check if you use atorvastatin (a cholesterol drug), take aluminum-containing products, use calcipotriene for psoriasis, or take any medications broken down by liver enzymes (CYP3A4 substrates), as vitamin D3 may affect these as well.

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.

This powder is designed to support muscle recovery and gut health with glutamine, vitamin D, and soluble fiber. It's worth considering if you're recovering from surgery, dealing with a critical illness, or looking to add more soluble fiber to your diet.

But if you take anticonvulsants, heart medications (verapamil, diltiazem, digoxin), blood pressure pills (thiazide diuretics), cholesterol drugs (atorvastatin), or any psoriasis medication, you'll need to check with your doctor or pharmacist first—vitamin D and glutamine can interact with these. Talk with your own healthcare provider about whether this product is right for you and your medications.

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

Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 31, 2018.

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 Muscle Fiber Unflavored Powder, straight from the product label.

Brand FINAFLEX
Barcode (UPC) 689466629118
Net contents 15.9 Oz(s); 450 Gram(s)
Market status On market
Date entered into DSLD Aug 31, 2018
DSLD ID 178098
Product type Other Combinations
Supplement form Powder
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 Muscle Fiber Unflavored Powder by FINAFLEX, 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:
7.5 Gram(s)
Maximum serving Sizes:
7.5 Gram(s)
Servings per container
60
UPC/BARCODE
689466629118
IngredientAmount% DV
Calories5 Calorie(s)--
Total Carbohydrates3 Gram(s)1%
L-Glutamine5 Gram(s)--
Dietary Fiber3 Gram(s)12%
Soluble Fiber3 Gram(s)--
Vitamin D3500 IU125%
Fructooligosaccharide3 Gram(s)--

Other ingredients: 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

Suggested use: As a dietary supplement consume 1 level scoop of Muscle Fiber 1-4 times daily. Add Muscle Fiber to 8-16 ounces of water or any flavored beverage and consume immediately after stirring. Drink Muscle Fiber every day to ensure proper daily dietary fiber and glutamine supplementation.

Contents may settle in transit. Shake container prior to use to redistribute ingredients.

FDA Statement of Identity

Dietary Supplement - 450 grams

Dietary Supplement

Precautions

Warning: Keep out of reach of children.

Do not use if pregnant or nursing.

Consult your doctor prior to use if you have or are at risk for prostate disease, heart disease, or any other general medical condition.

All persons are advised to consult with their doctor or other medical authority before use of this or any other dietary supplement. Discuss possible interactions and contradictions of this dietary supplement with other medicines currently prescribed by your doctor.

Discontinue use immediately if you experience any adverse symptoms or reactions while taking this product. Discontinue use 2 weeks prior to surgery. Do not use if your health status is unknown.

Storage

Store in a cool dry place (heat and humidity can cause clumping).

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.

General Statements

Made in USA

Sport performance Prevent muscle breakdown Increase muscle strength Makes taking fiber easier Flavorless powder 60 servings

Formula

Glutamine + Dietary Fiber

Prebiotic soluble Fiber

Muscle Fiber by FinaFlex combines a blend of two muscle preserving and strengthening ingredients with a prebiotic soluble Fiber.

Muscle Fiber with robust amino acid L-Glutamine, Vitamin D3, and Fructooligosaccharide (FOS), three ingredients that are crucial to muscle preservation, digestive health, and overall well being.

Brand IP Statement(s)

Muscle Fiber features two categories of ingredients that are often taken separately into one complete and novel dietary supplement.

Redefine yourself

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

See for yourself

Muscle Fiber Unflavored Powder by FINAFLEX label

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

Muscle Fiber Unflavored Powder 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 Muscle Fiber Unflavored Powder by FINAFLEX

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size7.5 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
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

Dietary Fiber

Interacts with
2,025 drugs
3 Gram(s) per serving

Black psyllium is a soluble-fiber supplement made from the seeds of a Plantago plant, used mostly to ease constipation and support digestive health. I...

Dietary Fiber monograph & interactions
  • › Soluble Fiber

Vitamin D3

Interacts with
715 drugs
500 IU per serving

Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and is important for healthy bones, muscles, and immune function. Many people,...

Vitamin D3 monograph & interactions

Fructooligosaccharide

No known
interactions
3 Gram(s) per serving

Fructo-oligosaccharides (FOS) are a type of soluble fiber that acts as a prebiotic, meaning they feed the helpful bacteria in your gut. They are gener...

Fructooligosaccharide monograph & interactions

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

Interaction report

Muscle Fiber Unflavored Powder by FINAFLEX Drug Interactions

Want to check YOUR meds against Muscle Fiber Unflavored Powder?

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
2,081Drugs
152 Moderate 1,929 Minor

Ingredients driving the most interactions

Dietary Fiber 2,025
Vitamin D3 715
L-Glutamine 50

Individual Drug Interactions

The ingredients in Muscle Fiber Unflavored Powder interact with 2,081 drugs. Click any drug to see the details.

3 of the 4 ingredients in Muscle Fiber Unflavored Powder interact with drugs. Each result below shows which ingredient is responsible. Dietary Fiber Vitamin D3 L-Glutamine

Each ingredient & the kinds of drugs it affects

For each ingredient in Muscle Fiber Unflavored Powder with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Dietary Fiber7 drug types · 2,025 drugs

Carbamazepine (Tegretol)

Theoretically, black psyllium might reduce the effects of carbamazepine and increase the risk for convulsions.
Theoretically, black psyllium might reduce carbamazepine absorption. A preliminary study using blond psyllium reported decreased carbamazepine bioavailability due to binding of the drug to psyllium, as well as reduction of available fluid in the gut for dissolution of the drug. This interaction may also occur with black psyllium.

Likelihood Probable Evidence D
Lithium

Theoretically, taking black psyllium at the same time as lithium might reduce lithium absorption.
The fiber in black psyllium might reduce lithium absorption and plasma levels. Some case reports describe a reduction in plasma lithium levels with concomitant administration of blond psyllium. This was reversed when psyllium was stopped. This interaction may also occur with black psyllium.

Likelihood Probable Evidence D
Metformin (Glucophage)

Theoretically, black psyllium might increase the therapeutic and adverse effects of metformin.
Animal research shows that concurrent consumption of blond psyllium with metformin slows and increases the absorption of metformin. This interaction may also occur with black psyllium. To avoid changes in absorption, take psyllium 30-60 minutes after metformin.

Likelihood Possible Evidence D
Olanzapine (Zyprexa)

Theoretically, taking black psyllium at the same time as olanzapine might reduce olanzapine absorption.
The fiber in black psyllium might decrease the absorption of olanzapine. A single case report describes a reduction in the effectiveness of olanzapine when it was concomitantly administered with an unspecified type of psyllium 3 grams orally twice daily. This effect was reversed when psyllium was stopped.

Likelihood Possible Evidence D
Digoxin (Lanoxin)

Theoretically, taking black psyllium at the same time as digoxin might reduce digoxin absorption and decrease digoxin levels.
Psyllium might bind digoxin in the gut. However, some clinical evidence suggests that psyllium does not impact digoxin absorption.

Likelihood Unlikely Evidence B
Ethinyl Estradiol

Theoretically, taking black psyllium at the same time as ethinyl estradiol might alter levels of estradiol.
Concurrent use of blond psyllium with ethinyl estradiol results in a slight increase in the extent of ethinyl estradiol absorption and a slower rate of absorption. This is unlikely to be clinically significant.

Likelihood Unlikely Evidence D
Oral Drugs

Theoretically, psyllium might increase, decrease, or have no effect on the absorption of oral drugs.
Psyllium seems to have variable effects on drug absorption. To avoid changes in absorption, take psyllium 30-60 minutes after oral medications. Animal research shows that blond psyllium delays and increases the absorption of metformin and ethinyl estradiol. Case reports and animal research suggest that blond psyllium might reduce absorption of lithium, digoxin, olanzapine, and carbamazepine. Finally, some pharmacokinetic studies show that psyllium does not affect the absorption of levothyroxine or warfarin. Although many of these studies evaluated blond psyllium, the fiber content in black psyllium may have similar effects.

Likelihood Possible Evidence B
Dietary Fiber full monograph & interactions

Vitamin D38 drug types · 715 drugs

Aluminum

Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
The protein that transports calcium across the intestinal wall can also bind and transport aluminum. This protein is stimulated by vitamin D, which may therefore increase aluminum absorption. This mechanism may contribute to increased aluminum levels and toxicity in people with renal failure, when they take vitamin D and aluminum-containing phosphate binders chronically.

Likelihood Probable Evidence B
Atorvastatin (Lipitor)

Vitamin D might reduce absorption of atorvastatin.
A small, low-quality clinical study shows that taking vitamin D reduces levels of atorvastatin and its active metabolites by up to 55%. However, while atorvastatin levels decreased, total cholesterol, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol levels did not substantially change. Atorvastatin is metabolized in the gut by CYP3A4 enzymes, and researchers theorized that vitamin D might induce CYP3A4, causing reduced levels of atorvastatin. However, this proposed mechanism was not specifically studied.

Likelihood Probable Evidence B
Calcipotriene (Dovonex)

Taking calcipotriene with vitamin D increases the risk for hypercalcemia.
Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia. Theoretically, combining calcipotriene with vitamin D supplements might increase the risk of hypercalcemia.

Likelihood Probable Evidence D
Digoxin (Lanoxin)

Theoretically, hypercalcemia induced by high-dose vitamin D can increase the risk of arrhythmia from digoxin.
High doses of vitamin D can cause hypercalcemia. Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and digoxin concurrently.

Likelihood Possible Evidence D
Diltiazem (Cardizem, Others)

Theoretically, hypercalcemia induced by high-dose vitamin D can reduce the therapeutic effects of diltiazem for arrhythmia.
High doses of vitamin D can cause hypercalcemia. Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically this could also occur with diltiazem. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and diltiazem concurrently.

Likelihood Probable Evidence B
Thiazide Diuretics

Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Thiazide diuretics decrease urinary calcium excretion, which could lead to hypercalcemia if vitamin D supplements are taken concurrently. This has been reported in people being treated with vitamin D for hypoparathyroidism, and also in elderly people with normal parathyroid function who were taking a thiazide, vitamin D, and calcium-containing antacids daily.

Likelihood Probable Evidence D
Verapamil (Calan, Others)

Hypercalcemia induced by high-dose vitamin D can reduce the therapeutic effects of verapamil for arrhythmia.
Hypercalcemia due to high doses of vitamin D can reduce the effectiveness of verapamil in atrial fibrillation. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and verapamil concurrently.

Likelihood Probable Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
There is some concern that vitamin D might induce CYP3A4. In vitro research suggests that vitamin D induces CYP3A4 transcription. Additionally, observational research has found that increased UV light exposure and serum vitamin D levels are associated with decreased serum levels of CYP3A4 substrates such as tacrolimus and sirolimus, while no association between UV light exposure or vitamin D levels and levels of mycophenolic acid, a non-CYP3A4 substrate, was found. A small, low-quality clinical study shows that taking vitamin D reduces levels of the CYP3A4 substrate atorvastatin and its active metabolites by up to 55%; however, the clinical effects of atorvastatin were not reduced. While researchers theorized that vitamin D might induce CYP3A4, this proposed mechanism was not specifically studied.

Likelihood Possible Evidence D
Vitamin D3 full monograph & interactions

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 Muscle Fiber Unflavored Powder, from the product label.

FINAFLEX

See all FINAFLEX products
Name
FinaFlex
Street Address
1190 Tidwell Road, Ste 304
City
Alpharetta
State
GA
ZipCode
30004
Web Address
www.FinaFlex.com
Pharmacist Counseling Corner

Muscle Fiber Unflavored Powder by FINAFLEX: Common Questions

Does Muscle Fiber Unflavored Powder by FINAFLEX interact with any medications?
Yes. Based on its ingredients, Muscle Fiber Unflavored Powder has a known interaction with 2,081 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Muscle Fiber Unflavored Powder contains 4 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 this safe to take if I'm pregnant or breastfeeding?
L-glutamine is likely safe in pregnancy, but there isn't enough data to know whether supplement doses are safe while breastfeeding—talk with your doctor or pharmacist before using it at these levels. Vitamin D3 is likely safe in pregnancy at recommended amounts but should be guided by your doctor; it's also likely safe while breastfeeding at recommended doses, though higher amounts need your doctor's okay. There's no pregnancy or breastfeeding data for the other ingredients in this product.
What side effects might I notice from the glutamine?
Common ones are belching, bloating, constipation, diarrhea, nausea, vomiting, headache, and stomach pain. Most people tolerate it well, but if you notice these or any other unusual symptoms, cut back or stop and talk with your pharmacist.
Will this powder cause gas or bloating from the fiber?
Yes, gas, bloating, and stomach pain are possible—especially at higher doses. But research on fructooligosaccharide shows that at doses under 10 grams daily, these symptoms are usually mild and don't happen any more often than they do with a placebo.
Can I take this if I have kidney or liver disease?
L-glutamine should only be used under medical supervision if you have kidney or liver disease. Talk with your doctor or pharmacist before starting this product if either applies to you.
What is L-glutamine actually for in this product?
L-glutamine is an amino acid your body uses during and after intense exercise and stress. It's effective for sickle cell disease and possibly helpful for recovery after surgery and certain serious illnesses involving wasting.
Does fructooligosaccharide really work for anything?
We don't have strong evidence in our data to support it for constipation, bone health, blood sugar, cholesterol, or traveler's diarrhea—the evidence is insufficient to rate. It's mainly there as a soluble fiber to support digestion and gut bacteria.

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.

Muscle Fiber Unflavored Powder label
Go deeper

The Full Monographs Behind Muscle Fiber Unflavored Powder’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

Black Psyllium

Interacts with 2,025 drugs

Black psyllium is a soluble-fiber supplement made from the seeds of a Plantago plant, used mostly to ease constipation and support digestive health. It is best known and most studied for rel...

Read the full Black Psyllium monograph → Herb & supplement monograph

Vitamin D

Interacts with 715 drugs

Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and is important for healthy bones, muscles, and immune function. Many people, especially those with low sun exposure,...

Read the full Vitamin D monograph → Herb & supplement monograph

Fructo-oligosaccharides (fos)

Fructo-oligosaccharides (FOS) are a type of soluble fiber that acts as a prebiotic, meaning they feed the helpful bacteria in your gut. They are generally considered safe for most people in...

Read the full Fructo-oligosaccharides (fos) monograph →
Sources

Sources & How We Checked

Muscle Fiber Unflavored Powder'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 61 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 →

Black Psyllium 18 references
  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  4. Etman M. Effect of a bulk forming laxative on the bioavailablility of carbamazepine in man. Drug Dev Ind Pharm 1995;21:1901-6.
  5. Perlman BB. Interaction between lithium salts and ispaghula husk. Lancet 1990;335:416.
  6. Vaswani SK, Hamilton RG, Valentine MD, Adkinson NF. Psyllium laxative-induced anaphylaxis, asthma, and rhinitis. Allergy 1996;51:266-8. PubMed
  7. Lantner RR, Espiritu BR, Zumerchik P, Tobin MC. Anaphylaxis following ingestion of a psyllium-containing cereal. JAMA 1990;264:2534-6. DOI
  8. Kaplan MJ. Anaphylactic reaction to "Heartwise." N Engl J Med 1990;323:1072-3. DOI
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See these in context on the Black Psyllium monograph →

Vitamin D 26 references
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Fructo-oligosaccharides (fos) 6 references
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See these in context on the Fructo-oligosaccharides (fos) 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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