Interactions on record — worth a quick check against your medications. Based on 7 of 11 ingredients. Check your meds →
Dietary supplement

Fiber Blend Ingredients & Drug Interactions

by The Vitamin Shoppe

Fiber Blend 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 Fiber Blend 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

Fiber Blend is a dietary supplement by The Vitamin Shoppe with 11 active ingredients. Its ingredients are commonly taken for constipation, diarrhea, high cholesterol.Based on those ingredients, 2,088 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Dietary Fiber, Cabbage, Broccoli. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Fiber Blend by The Vitamin Shoppe

Ask about any prescription or over-the-counter medication and we check it for interactions with Fiber Blend by The Vitamin Shoppe — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Fiber Blend by The Vitamin Shoppe

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

Fiber Blend contains 10 ingredients, including carrot, apple pectin, prune, citrus pectin, brown rice bran, soy fiber, oat fiber, psyllium husk, cabbage, and broccoli. The pectin and fiber sources work to support digestive health and bowel regularity.

Carrot and broccoli also supply compounds and vitamins. The product includes inactive ingredients — gelatin (capsule material), magnesium stearate, and modified cellulose — to form and stabilize the capsules.

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
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: digestive health and regularity.
  • We looked for evidence on: Constipation, Diarrhea, Irritable bowel syndrome (IBS), Gastritis, Peptic ulcers, Postoperative ileus — and 3 related terms.
  • The strongest evidence on file: Black Psyllium is rated "Effective" for Constipation (Natural Medicines).
  • Also on file: Plum is rated "Possibly Effective" for Constipation.
  • Also on file: Black Psyllium is rated "Insufficient Reliable Evidence To Rate" for Diarrhea.

Apple pectin and citrus pectin (the same ingredient listed twice) are possibly effective for high cholesterol. Prune is possibly effective for constipation.

Brown rice bran is possibly effective for high cholesterol and lipid problems. Carrot is possibly effective for vitamin A deficiency.

Broccoli is possibly effective for colorectal cancer prevention. For most other claimed uses in this blend — including prediabetes, cancer prevention in other sites, and bone health — the evidence in our data is insufficient to establish effectiveness.

The evidence, ingredient by ingredient Black Psyllium Carrot Pectin Plum Rice Bran Cabbage Broccoli

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 7 of the 7 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 7 of 7.
  • General safety write-ups exist for 7 of 7.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

All checked ingredients are generally well tolerated as foods. Carrot, apple pectin, citrus pectin, brown rice bran, cabbage, and broccoli all carry a caution that concentrated supplement forms have less safety data than food amounts.

Common side effects from the fiber and bran content include gas, loose stools, mild cramping, flatulence, and abdominal discomfort — these may ease as your body adjusts. Allergic reactions are rare but possible; carrot, pectin, rice bran, cabbage, and broccoli have all been reported to cause allergic reactions in sensitive individuals, ranging from hives and swelling to anaphylaxis in rare cases.

For pregnancy, carrot is rated Likely Safe, both pectins are Likely or Possibly Safe, and brown rice bran and broccoli are Likely Safe; the pregnancy safety data for prune and soy fiber are not fully on file. For breastfeeding, apple pectin and citrus pectin safety is not well studied in supplement form — talk with your doctor or pharmacist before use.

Brown rice bran and broccoli are considered safe during breastfeeding as foods.

Side effects, ingredient by ingredient Black Psyllium Carrot Pectin Plum Rice Bran Cabbage Broccoli

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?
  • 5 of the 7 matched ingredients can interact with medications — Black Psyllium, Cabbage, Pectin, Broccoli, Plum.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; heart-rhythm medications; lithium.
  • For scale: 2,089 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 taking Fiber Blend, check with your doctor or pharmacist if you take any of these: cholesterol medications (lovastatin), tetracycline antibiotics, heart medications (digoxin), blood thinners or antiplatelet drugs, diabetes medications, acetaminophen, blood thinners like warfarin, anti-anxiety medications (oxazepam), or any drug metabolized through your liver's cytochrome P450 system. The pectin and cruciferous vegetables in this blend may reduce how well these drugs work or change their levels in your blood.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This is a multi-ingredient fiber blend suited for digestive support and constipation relief, with some ingredients studied for cholesterol and cancer prevention. If you take heart medications (digoxin, lovastatin), antibiotics (tetracyclines), blood thinners (warfarin, antiplatelet drugs), diabetes medication, anti-anxiety medication (oxazepam), or acetaminophen, check your exact medications with the tool on this page before starting, or talk with your doctor or pharmacist.

If you're pregnant or breastfeeding, discuss this product with your healthcare provider first.

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

Assessment coverage: 8 of 11 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 24, 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 Fiber Blend, straight from the product label.

Brand The Vitamin Shoppe
Barcode (UPC) 766536011919
Net contents 300 Capsule(s)
Market status On market
Date entered into DSLD Jun 24, 2019
DSLD ID 203552
Product type Botanical With Nutrients
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, 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 Fiber Blend by The Vitamin Shoppe, 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:
3 Capsule(s)
Maximum serving Sizes:
3 Capsule(s)
Servings per container
100
UPC/BARCODE
766536011919
IngredientAmount% DV
Total Carbohydrates1 Gram(s)1%
Dietary Fiber1 Gram(s)4%
Carrot9 mg--
Apple Pectin210 mg--
Prune75 mg--
Citrus Pectin150 mg--
Brown Rice Bran825 mg--
Soy Fiber150 mg--
Oat Fiber930 mg--
Psyllium Husk120 mg--
Cabbage18 mg--
Broccoli6 mg--

Other ingredients: Gelatin, Magnesium Stearate, Modified Cellulose

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formula

A source of insoluble and soluble fiber

Contains: Soy.

Warning: This product must be taken with at least 8 oz. of water, as it contains Psyllium Husks.

Fiber Blend capsules contain fiber from all 6 fiber groups: cellulose, pectin, gums and mucilages, hemicellulose and lignin.

General Statements

Specialty

Digestive health Regularity

Visit www.vitaminshoppe.com or call 1-800-223-1216 for more information and to reorder.

FDA Statement of Identity

Dietary Supplement

Formulation

Gluten free Dairy free Nut free

Does not contain: Gluten, salt, artificial colors or flavors.

Precautions

Contains: Soy.

Warning: This product must be taken with at least 8 oz. of water, as it contains Psyllium Husks. Taking Psyllium Husks without a full glass of liquid may cause choking.

Do not use this product if you are pregnant, nursing or have difficulty swallowing.

Keep out of reach of children.

Tamper evident Do not use if outer seal is broken or missing.

Suggested/Recommended/Usage/Directions

Directions: Take three (3) capsules up to twice daily with at least 8 oz. of water and preferably with meals.

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.

Storage

Store in a cool, dry place.

Seals/Symbols

Quality Promise Tested Trusted Guaranteed 30 day money back guarantee

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

See for yourself

Fiber Blend by The Vitamin Shoppe label

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

Fiber Blend 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 Fiber Blend by The Vitamin Shoppe

These are the 11 active ingredients this product is made of. Select any to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container100 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.

Dietary Fiber

Interacts with
2,025 drugs
1 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

Carrot

No known
interactions
9 mg per serving

Carrot is a common food vegetable that is a rich source of beta-carotene (which the body turns into vitamin A) and other nutrients. Eating carrots is...

Carrot monograph & interactions

Apple Pectin

Interacts with
23 drugs
210 mg per serving

Pectin is a natural soluble fiber found in fruits like apples and citrus, and it is widely used in foods and as a fiber supplement. It may modestly he...

Apple Pectin monograph & interactions

Prune

Interacts with
122 drugs
75 mg per serving

Plums and their dried form (prunes) are common, nutritious foods that are best known for helping relieve constipation thanks to their fiber and sorbit...

Prune monograph & interactions

Citrus Pectin

Interacts with
23 drugs
150 mg per serving

Pectin is a natural soluble fiber found in fruits like apples and citrus, and it is widely used in foods and as a fiber supplement. It may modestly he...

Citrus Pectin monograph & interactions

Brown Rice Bran

No known
interactions
825 mg per serving

Rice bran is the nutrient-rich outer layer of the rice grain and is a good source of fiber, healthy fats, and plant compounds. It is most studied for...

Brown Rice Bran monograph & interactions

Soy Fiber

150 mg per serving

Oat Fiber

930 mg per serving

Psyllium Husk

120 mg per serving

Cabbage

Interacts with
325 drugs
18 mg per serving

Cabbage is a nutritious, low-calorie vegetable that is safe to eat as food and is sometimes applied to the skin as a leaf wrap for breast engorgement...

Cabbage monograph & interactions

Broccoli

Interacts with
187 drugs
6 mg per serving

Broccoli is a nutritious cruciferous vegetable rich in fiber, vitamins, and plant compounds like sulforaphane that have drawn scientific interest for...

Broccoli monograph & interactions

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

Interaction report

Fiber Blend by The Vitamin Shoppe Drug Interactions

Want to check YOUR meds against Fiber Blend?

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
2,088Drugs
440 Moderate 1,648 Minor

Ingredients driving the most interactions

Dietary Fiber 2,025
Cabbage 325
Broccoli 187
Prune 122
Apple Pectin 23

Individual Drug Interactions

The ingredients in Fiber Blend interact with 2,088 drugs. Click any drug to see the details.

5 of the 11 ingredients in Fiber Blend interact with drugs. Each result below shows which ingredient is responsible. Dietary Fiber Cabbage Broccoli Prune Apple Pectin

Each ingredient & the kinds of drugs it affects

For each ingredient in Fiber Blend 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

Cabbage6 drug types · 325 drugs

Acetaminophen (Tylenol, Others)

Cabbage might increase clearance and reduce the effects of acetaminophen.
A small clinical study shows that daily consumption of cabbage and Brussels sprout decreases acetaminophen levels by as much as 16%, with some evidence suggesting that this effect is due to increased elimination through glucuronide conjugation.

Likelihood Probable Evidence B
Antidiabetes Drugs

Theoretically, cabbage might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal and in vivo research suggests that cabbage might have hypoglycemic effects.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, cabbage might decrease levels of drugs metabolized by CYP1A2.
Some animal research suggests that cabbage or its constituent indole-3-carbinol might increase drug metabolism and elimination by stimulating CYP1A2 activity.

Likelihood Possible Evidence D
Glucuronidated Drugs

Theoretically, cabbage might increase clearance and decrease the effects of drugs metabolized through glucuronide conjugation.
A small clinical study shows that daily consumption of cabbage and Brussels sprout decreases levels of some drugs metabolized through glucuronide conjugation.

Likelihood Probable Evidence B
Oxazepam (Serax)

Cabbage might increase clearance and reduce the effects of oxazepam.
A small clinical study shows that daily consumption of cabbage and brussels sprout decreases oxazepam levels by as much as 17%, with some evidence suggesting that this effect is due to increased elimination through glucuronide conjugation.

Likelihood Probable Evidence B
Warfarin (Coumadin)

Theoretically, cabbage might decrease the anticoagulant effects of warfarin.
Cabbage contains vitamin K. If consumed in large quantities, cabbage might decrease the anticoagulant effects of warfarin.

Likelihood Possible Evidence D
Cabbage full monograph & interactions

Broccoli2 drug types · 187 drugs

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, broccoli might reduce the levels and effects of drugs metabolized by CYP1A2.
Pharmacokinetic research in humans shows that eating 500 grams of fresh broccoli daily for 6-12 days can increase CYP1A2 activity by 10% to 200%. Induction of CYP1A2 activity by broccoli is attributed to its glucosinolate constituents.

Likelihood Possible Evidence B
Cytochrome P450 2A6 (Cyp2A6) Substrates

Theoretically, broccoli might reduce the levels and effects of drugs metabolized by CYP2A6.
Pharmacokinetic research in humans shows that eating 500 grams of broccoli daily for 6 days increases CYP2A6 activity by 135% to 550%. Induction of CYP2A6 activity is attributed to its glucosinolate constituents.

Likelihood Possible Evidence B
Broccoli full monograph & interactions

Prune1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, plum juice might have antiplatelet effects.
Consuming plum juice while taking anticoagulant or antiplatelet drugs might increase the risk of bruising and bleeding. In healthy volunteers, drinking plum juice 200 mL daily for 28 days prolonged clotting time and inhibited platelet aggregation.

Likelihood Possible Evidence B
Prune full monograph & interactions

Apple Pectin3 drug types · 23 drugs

Digoxin (Lanoxin)

Theoretically, pectin might reduce the absorption of digoxin, potentially decreasing its effectiveness.
A small clinical study shows that taking digoxin with a kaolin-pectin suspension reduces the absorption of digoxin by about 62%. It is unclear if these effects are due to pectin, kaolin, or the combination.

Likelihood Possible Evidence B
Lovastatin (Mevacor)

Theoretically, pectin might reduce the absorption of lovastatin, potentially decreasing its effectiveness.
Case reports suggest that concomitant use of pectin and lovastatin might reduce the cholesterol-lowering effect of lovastatin, possibly due to reduced intestinal absorption of lovastatin.

Likelihood Possible Evidence D
Tetracycline Antibiotics

Theoretically, pectin might reduce the absorption of tetracycline antibiotics, potentially decreasing their effectiveness.
A small clinical study shows that taking tetracycline with bismuth subsalicylate in a kaolin-pectin suspension reduces the absorption of tetracycline by about 34%. It is unclear if these effects are due to pectin, kaolin, bismuth subsalicylate, or the combination.

Likelihood Possible Evidence B
Apple Pectin full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Fiber Blend, from the product label.

The Vitamin Shoppe

See all The Vitamin Shoppe products
Name
Vitamin Shoppe, Inc.
City
Secaucus
State
NJ
ZipCode
07094
Phone Number
1-800-223-1216
Web Address
www.vitaminshoppe.com
Pharmacist Counseling Corner

Fiber Blend by The Vitamin Shoppe: Common Questions

Does Fiber Blend by The Vitamin Shoppe interact with any medications?
Yes. Based on its ingredients, Fiber Blend has a known interaction with 2,088 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Fiber Blend contains 11 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 constipation?
Prune in this blend is possibly effective for constipation relief. Fiber ingredients like psyllium husk, oat fiber, and soy fiber are included to support digestive health and bowel regularity, though the evidence data we hold for those specific ingredients is not documented here.
Can I take this if I'm pregnant or breastfeeding?
Carrot, brown rice bran, and broccoli are rated Likely Safe during pregnancy and breastfeeding. Both pectins are Likely or Possibly Safe in pregnancy. Prune and the safety data for soy fiber in pregnancy are not fully documented. Pectin supplement forms and concentrated broccoli extracts have not been well studied while breastfeeding. Talk with your doctor or pharmacist before use.
What does the fiber do?
The pectin, fiber, and bran ingredients support digestive health and help add bulk to your stool. Apple pectin and citrus pectin are possibly effective for high cholesterol. Brown rice bran is also possibly effective for cholesterol and lipid balance.
Are there any common side effects?
Gas, loose stools, mild cramping, flatulence, and abdominal discomfort are the most common side effects from fiber and bran ingredients. These often settle as your body adjusts. Allergic reactions are rare but can occur in sensitive people.
Does this contain any allergens?
Carrot, pectin, rice bran, cabbage, and broccoli have all been reported to cause allergic reactions in sensitive individuals. Anaphylaxis is rare but has been documented with pectin and rice bran. If you have a history of food allergies, especially to vegetables or brassicas (broccoli, cabbage), talk with your doctor before use.
Is this safe for children?
The product facts do not include safety data for children. Talk with your child's doctor or pharmacist before giving this to them.

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.

Fiber Blend label
Go deeper

The Full Monographs Behind Fiber Blend’s Ingredients

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

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

Carrot

Carrot is a common food vegetable that is a rich source of beta-carotene (which the body turns into vitamin A) and other nutrients. Eating carrots is safe and nutritious for most people, but...

Read the full Carrot monograph → Herb & supplement monograph

Pectin

Interacts with 23 drugs

Pectin is a natural soluble fiber found in fruits like apples and citrus, and it is widely used in foods and as a fiber supplement. It may modestly help with cholesterol, blood sugar, and di...

Read the full Pectin monograph → Herb & supplement monograph

Plum

Interacts with 122 drugs

Plums and their dried form (prunes) are common, nutritious foods that are best known for helping relieve constipation thanks to their fiber and sorbitol content. They are generally safe as f...

Read the full Plum monograph → Herb & supplement monograph

Rice Bran

Rice bran is the nutrient-rich outer layer of the rice grain and is a good source of fiber, healthy fats, and plant compounds. It is most studied for helping lower cholesterol, but for most...

Read the full Rice Bran monograph → Herb & supplement monograph

Cabbage

Interacts with 325 drugs

Cabbage is a nutritious, low-calorie vegetable that is safe to eat as food and is sometimes applied to the skin as a leaf wrap for breast engorgement or sore joints. Most medicinal claims ar...

Read the full Cabbage monograph → Herb & supplement monograph

Broccoli

Interacts with 187 drugs

Broccoli is a nutritious cruciferous vegetable rich in fiber, vitamins, and plant compounds like sulforaphane that have drawn scientific interest for health benefits. Eating broccoli as food...

Read the full Broccoli monograph →
Sources

Sources & How We Checked

Fiber Blend'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 80 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.

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
  9. Nordstrom M, Melander A, Robertsson E, Steen B. Influence of wheat bran and of a bulk-forming ispaghula cathartic on the bioavailability of digoxin in geriatric in-patients. Drug Nutr Interact 1987;5:67-9..
  10. Robinson DS, Benjamin DM, McCormack JJ. Interaction of warfarin and nonsystemic gastrointestinal drugs. Clin Pharmacol Ther 1971;12:491-5. PubMed
  11. Garcia JJ, Fernandez N, Diez MJ, et al. Influence of two dietary fibers in the oral bioavailability and other pharmacokinetic parameters of ethinyloestradiol. Contraception 2000;62:253-7. PubMed
  12. Fernandez N, Lopez C, Díez R, et al. Drug interactions with the dietary fiber Plantago ovata husk. Expert Opin Drug Metab Toxicol 2012;8(11):1377-86.
  13. Semen plantaginis in: WHO Monographs on Selected Medicinal Plants, volume 1. World Health Organization, Geneva, 1999. Available at http://apps.who.int/medicinedocs/en/d/Js2200e/. Accessed November 26, 1026.
  14. Code of Federal Regulations, Title 21 (21CFR 101.17). Food labeling warning, notice, and safe handling statements. Available at www.ecfr.gov/cgi-bin/text-idx?SID=20f647d3b74161501f46564b915b4048&mc=true&node=se21.2.101_117&rgn=div8. Accessed December 3, 2
  15. Code of Federal Regulations, Title 21 (21CFR 201.319). Specific labeling requirements - water-soluble gums, hydrophilic gums, and hydrophilic mucilloids. Available at www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=201.319. Accessed Dece
  16. Diez R, Garcia JJ, Diez MJ, Sierra M, Sahagun AM, Fernandez N. Influence of Plantago ovata husk (dietary fiber) on the bioavailability and other pharmacokinetic parameters of metformin in diabetic rabbits. BMC Complement Altern Med. 2017 Jun 7;17(1):298. PubMed
  17. Chiu AC, Sherman SI. Effects of pharmacological fiber supplements on levothyroxine absorption. Thyroid. 1998;8(8):667-71. PubMed
  18. Merrick C, Madden CA, Capurso NA. A Case of Blunted Orally Disintegrating Olanzapine Effect Due to Coadministered Psyllium. J Clin Psychiatry 2021;82(2):20cr13633. PubMed

See these in context on the Black Psyllium monograph →

Carrot 14 references
  1. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  2. Wetzel WE, Lehn W, Grieb A. [Carotene jaundice in infants with "sugar nursing bottle syndrome"]. Monatsschr Kinderheilkd 1989;137(10):659-61.
  3. el-Arab AE, Khalil F, Hussein L. Vitamin A deficiency among preschool children in a rural area of Egypt: the results of dietary assessment and biochemical assay. Int J Food Sci Nutr 2002;53(6):465-74. PubMed
  4. Helbling A. [Food allergy]. Ther Umsch 1994;51(1):31-7.
  5. Kaplan R. Carrot addiction. Aust N Z J Psychiatry 1996;30(5):698-700.
  6. Ncube, T. N., Greiner, T., Malaba, L. C., and Gebre-Medhin, M. Supplementing lactating women with puréed papaya and grated carrots improved vitamin A status in a placebo-controlled trial. J Nutr 2001;131(5):1497-1502. PubMed
  7. Mullins M, Froelke BR, Rivera MR. Effect of delayed activated charcoal on acetaminophen concentration after simulated overdose of oxycodone and acetaminophen. Clin Toxicol (Phila) 2009;47(2):112-5. PubMed
  8. Kawai M, Tamagawa-Mineoka R, Hagura A, Masuda K, Katoh N. Allergic contact dermatitis due to carrots. J Dermatol 2014;41(8):753-4. PubMed
  9. Xu X, Cheng Y, Li S, et al. Dietary carrot consumption and the risk of prostate cancer. Eur J Nutr 2014;53(8):1615-23. PubMed
  10. Donaldson MS, Speight N, Loomis S. Fibromyalgia syndrome improved using a mostly raw vegetarian diet: an observational study. BMC Complement Altern Med. 2001;1:7. PubMed
  11. Chen H, Shao F, Zhang F, Miao Q. Association between dietary carrot intake and breast cancer: A meta-analysis. Medicine (Baltimore). 2018;97(37):e12164. PubMed
  12. Bosanac SS, Clark AK, Sivamani RK. Phytophotodermatitis related to carrot extract-containing sunscreen. Dermatol Online J. 2018;24(1). pii: 13030/qt2nv2d1n0. DOI
  13. Deding U, Baatrup G, Christensen LP, Kobaek-Larsen M. Carrot Intake and Risk of Colorectal Cancer: A Prospective Cohort Study of 57,053 Danes. Nutrients 2020;12(2):332. PubMed
  14. Sánchez-Guerrero IM, Nieto A, Meseguer J, et al. Occupational Rhinoconjunctivitis Induced by Unusual Allergens of Carrot. J Investig Allergol Clin Immunol 2020;30(3):204-206. PubMed

See these in context on the Carrot monograph →

Pectin 11 references
  1. Jaakkola MS, et al. Asthma caused by occupational exposure to pectin. J Allergy Clin Immunol 1997;100:575-6. PubMed
  2. Westphal W, et al. [Exogenous allergic asthma following pectin exposure-a new occupational allergen]. Pneumologie 1990;44(Suppl 1):337-8.
  3. Baldwin JL, et al. Pectin-induced occupational asthma. Chest 1993;104:1936-7. PubMed
  4. Cohen AJ, Forse MS, Tarlo SM. Occupational asthma caused by pectin inhalation during the manufacture of jam. Chest 1993;103:309-11.
  5. Kraut A, et al. Christmas candy maker's asthma. IgG4-mediated pectin allergy. Chest 1992;102:1605-7. PubMed
  6. Richter WO, Jacob BG, Schwandt P. Interaction between fibre and lovastatin. Lancet 1991;338:706.
  7. Albert KS, Ayres JW, DiSanto AR, et al. Influence of kaolin-pectin suspension on digoxin bioavailability. J Pharm Sci 1978;67:1582-6. PubMed
  8. Albert KS, Welch RD, DeSante KA, et al. Decreased tetracycline bioavailability caused by a bismuth subsalicylate antidiarrheal mixture. J Pharm Sci 1979;68:586-8. PubMed
  9. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  10. Federal Register April 17,2003. Anti-Diarrheal Products for over-the-counter human use; final monograph. Available at: http://www.fda.gov/OHRMS/DOCKETS/98fr/03-9380.pdf (Accessed 27 December 2004).
  11. Washio K, Nakamura M, Sato N, et al. Anaphylaxis in a pectin- and cashew nut-allergic child caused by a citrus bath. Allergol Int 2022;71(1):155-157. PubMed

See these in context on the Pectin monograph →

Plum 10 references
  1. Lever E, Cole J, Scott SM, Emery PW, Whelan K. Systematic review: the effect of prunes on gastrointestinal function. Aliment Pharmacol Ther. 2014;40(7):750-8. PubMed
  2. Hooshmand S, Chai SC, Saadat RL, et al. Comparative effects of dried plum and dried apple on bone in postmenopausal women. Br J Nutr. 2011;106(6):923-30. PubMed
  3. Ibrahim N, Chauhan I, Nikkar-Esfahani A. 'A problematic plum pit in the piping': a case of traumatic oesophageal perforation. BMJ Case Rep. 2016;2016. pii: bcr2015213807. PubMed
  4. Piirainen L, Peuhkuri K, Bäckström K, Korpela R, Salminen S. Prune juice has a mild laxative effect in adults with certain gastrointestinal symptoms. Nutr. Res. 2007;27(8):511-3. DOI
  5. Kong MS, Wang KL. A prune-induced small intestinal obstruction: sonographic appearance. J Clin Ultrasound. 1995;23(9):558-60. PubMed
  6. Jain M, Pielage P, De-Ryke R. Plum stones: an unusual cause of ileostomy obstruction demonstrated by sonography. J Clin Ultrasound. 1998;26(8):416-7. DOI
  7. Arjmandi BH, Khalil DA, Lucas EA, et al. Dried plums improve indices of bone formation in postmenopausal women. J Womens Health Gend Based Med. 2002;11(1):61-8. PubMed
  8. Santhakumar AB, Kundur AR, Fanning K, Netzel M, Stanley R, Singh I. Consumption of anthocyanin-rich Queen Garnet plum juice reduces platelet activation related thrombogenesis in healthy volunteers. J. Functional Foods. 2015;12:11-22. DOI
  9. Santhakumar AB, Kundur AR, Sabapathy S, Stanley R, Singh I. The potential of anthocyanin-rich Queen Garnet plum juice supplementation in alleviating thrombotic risk under induced oxidative stress conditions. J. Functional Foods. 2015;14:747-57. DOI
  10. Johnson MC, Fisher JK. Plum pit ileus: a case report. Mo Med. 1991;88(10):696-8.

See these in context on the Plum monograph →

Rice Bran 7 references
  1. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  2. Fujiwaki T, Furusho K. The effects of rice bran broth bathing in patients with atopic dermatitis. Acta Paediatr Jpn 1992;34:505-10.
  3. Uenotsuchi T, Satoh E, Kiryu H, Yano Y. Pyemotes dermatitis caused by indirect contact with husk rice. Br J Dermatol 2000;143:680-2. DOI
  4. Satoh R, Tsuge I, Tokuda R, Teshima R. Analysis of the distribution of rice allergens in brown rice grains and of the allergenicity of products containing rice bran. Food Chem. 2019;276:761-767. PubMed
  5. Togashi Y, Inomata N, Suzuki A, Hakuta A, Aihara M. Pediatric case with rice bran allergy induced by epicutaneous sensitization in a family rice shop. Allergol Int. 2019;68(1):117-118. PubMed
  6. So WKW, Chan JYW, Law BMH, et al. Effects of a Rice Bran Dietary Intervention on the Composition of the Intestinal Microbiota of Adults with a High Risk of Colorectal Cancer: A Pilot Randomised-Controlled Trial. Nutrients 2021;13(2):526. PubMed
  7. Haneda Y, Kadowaki S, Furui M, Taketani T. A pediatric case of food-dependent exercise-induced anaphylaxis due to rice bran. Asia Pac Allergy 2021;11(1):e4. PubMed

See these in context on the Rice Bran monograph →

Cabbage 15 references
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Pantuck EJ, Pantuck CB, Anderson KE, et al. Effect of brussels sprouts and cabbage on drug conjugation. Clin Pharmacol Ther 1984;35:161-9. PubMed
  3. Roberts KL. A comparison of chilled cabbage leaves and chilled gelpaks in reducing breast engorgement. J Hum Lact 1995;11:17-20. PubMed
  4. Roberts KL, Reiter M, Schuster D. A comparison of chilled and room temperature cabbage leaves in treating breast engorgement. J Hum Lact 1995;11:191-4. PubMed
  5. Roberts KL, Reiter M, Schuster D. Effects of cabbage leaf extract on breast engorgement. J Hum Lact 1998;14:231-6. PubMed
  6. Nikodem VC, Danziger D, Gebka N, et al. Do cabbage leaves prevent breast engorgement? A randomized, controlled study. Birth 1993;20:61-4. PubMed
  7. Balk JL. Indole-3-carbinol for cancer prevention. Altern Med Alert 2000; 3:105-7.
  8. He YH, Friesen MD, Ruch RJ, Schut HA. Indole-3-carbinol as a chemopreventive agent in 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) carcinogenesis: inhibition of PhIP-DNA adduct formation, acceleration of PhIP metabolism, and induction of cytoch
  9. Platel, K. and Srinivasan, K. Plant foods in the management of diabetes mellitus: vegetables as potential hypoglycaemic agents. Nahrung 1997;41(2):68-74. PubMed
  10. Steinkellner, H., Rabot, S., Freywald, C., Nobis, E., Scharf, G., Chabicovsky, M., Knasmuller, S., and Kassie, F. Effects of cruciferous vegetables and their constituents on drug metabolizing enzymes involved in the bioactivation of DNA-reactive dietary c
  11. Dolle S, Hompes S, Lange L, Worm M. Cabbage allergy: a rare cause of food-induced anaphylaxis. Acta Derm Venereol 2013;93(4):485-6. PubMed
  12. Lauche R, Graf N, Cramer H, Al-Abtah J, Dobos G, Saha FJ. Efficacy of cabbage leaf wraps in the treatment of symptomatic osteoarthritis of the knee: a randomized controlled trial. Clin J Pain 2016;32(11):961-71. PubMed
  13. Lim AR, Song JA, Hur MH, Lee MK, Lee MS. Cabbage compression early breast care on breast engorgement in primiparous women after cesarean birth: a controlled trial. Int J Clin Exp Med 2015;8(11):21335-42.
  14. Milanesi N, Gola M. Irritant contact dermatitis caused by Savoy cabbage. Contact Dermatitis 2016;74(1):60-1. PubMed
  15. Saini P, Saini R. Cabbage leaves and breast engorgement. Indian J Public Health 2014;58(4):291-2. PubMed

See these in context on the Cabbage monograph →

Broccoli 5 references
  1. Kristal AR, Lampe JW. Brassica vegetables and prostate cancer risk: a review of the epidemiological evidence. Nutr Cancer 2002;42:1-9. PubMed
  2. Chakrabarti A, Prais L, Foulds IS. Allergic contact dermatitis to broccoli. Br J Dermatol 2003;148:172-3. PubMed
  3. Hakooz, N. and Hamdan, I. Effects of dietary broccoli on human in vivo caffeine metabolism: a pilot study on a group of Jordanian volunteers. Curr Drug Metab 2007;8(1):9-15. PubMed
  4. Kall MA, Vang O, Clausen J. Effects of dietary broccoli on human drug metabolising activity. Cancer Lett. 1997;114(1-2):169-70. PubMed
  5. Bauman JE, Hsu CH, Centuori S, et al. Randomized Crossover Trial Evaluating Detoxification of Tobacco Carcinogens by Broccoli Seed and Sprout Extract in Current Smokers. Cancers (Basel). 2022;14(9):2129. Published 2022 Apr 24. PubMed

See these in context on the Broccoli monograph →

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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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