Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Glucomannan Ingredients & Drug Interactions

by The Vitamin Shoppe

Glucomannan label
See full label image
Capsule Category: Fiber And Other Nutrients
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Glucomannan 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

Glucomannan is a dietary supplement by The Vitamin Shoppe with 1 active ingredient. Its ingredients are commonly taken for weight loss and appetite control, constipation, high cholesterol.Based on those ingredients, 2,022 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Glucomannan. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Glucomannan by The Vitamin Shoppe

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Glucomannan 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 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: glucomannan, a soluble fiber derived from the konjac plant root. It works by absorbing water and forming a thick, gel-like substance in your digestive tract.

The capsule also contains inactive ingredients — gelatin (the capsule shell itself), rice flour, magnesium stearate, and silicon dioxide — which are fillers and binders that help the product hold together.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: help maintain normal blood glucose levels.
  • We looked for evidence on: Diabetes, Metabolic syndrome, blood sugar control, glycemic management.
  • The strongest evidence on file: Glucomannan is rated "Possibly Effective" for Diabetes (Natural Medicines).
  • Also on file: Glucomannan is rated "Insufficient Reliable Evidence To Rate" for Metabolic syndrome.

Glucomannan has possibly effective evidence for constipation, type 2 diabetes, and high cholesterol (hyperlipidemia). For high blood pressure, the evidence we have is insufficient to rate whether it works.

This means glucomannan may help with digestion and some metabolic conditions, but the strength of that evidence varies — talk with your doctor about what you're hoping to manage and whether this fits your health goals.

The evidence, ingredient by ingredient Glucomannan

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.

When taken with plenty of water, glucomannan is generally well tolerated. The most common side effects are belly pain, bloating, constipation, diarrhea, gas, nausea, and vomiting — especially at doses over 3 grams daily.

Rarely, it can cause choking or blockage in your food pipe or intestines, particularly if swallowed dry or without enough liquid. For pregnancy, there isn't enough reliable safety data to know either way — talk with your doctor before using it while pregnant.

Little is known about safety while breastfeeding, so caution is advised; check with your doctor or pharmacist for personalized guidance.

Side effects, ingredient by ingredient Glucomannan

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 — Glucomannan.
  • The most serious interaction on file is rated Moderate.
  • For scale: 2,023 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 glucomannan, check with your doctor or pharmacist about any oral medications you're taking — this product may lower how much of them your body absorbs. The interaction is Moderate severity and applies broadly to oral drugs, so timing matters: take your medications and glucomannan separately, a couple of hours apart if possible.

Check your own medication Run your meds through the checker above

The bottom line

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

Glucomannan may help with constipation, blood sugar control, or cholesterol if the evidence supports your specific goal — but it can interfere with how your body absorbs oral medications. If you take any prescription or over-the-counter drugs, space them away from glucomannan by a couple of hours and confirm the timing with your doctor or pharmacist.

Always take it with plenty of water to avoid choking or blockage. Pregnant or breastfeeding?

Talk it over with your healthcare provider first.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Sep 22, 2016.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Glucomannan, straight from the product label.

Brand The Vitamin Shoppe
Barcode (UPC) 766536023639
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Sep 22, 2016
DSLD ID 65001
Product type Fiber And Other Nutrients
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar 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 Glucomannan 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
33
UPC/BARCODE
766536023639
IngredientAmount% DV
Glucomannan1.99 Gram(s)--

Other ingredients: Gelatin, Rice Flour, Magnesium Stearate, Silicon Dioxide

Tap any ingredient to jump to its full detail below.

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

Helps maintain blood glucose levels already within the normal range. May promote feeling of fullness.

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

Specialty

Supports feeling full

Actual size

General

Item No. VS-2363 1615509 HQ 1

FDA Statement of Identity

Dietary Supplement

Formula

A source of soluble fiber from konjac root

Formulation

Gluten free Dairy free Soy free Nut free

Does not contain: Yeast, Corn, Wheat, Gluten, Sugar, Soy, Salt, Citrus, Fish, Dairy, Preservatives, Artificial Flavors.

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Storage

Store in a cool, dry place.

Precautions

Keep out of reach of children.

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

Warning: Do not take if you are pregnant or nursing.

Do not take before going to bed.

Consult your physician prior to use if you are taking any antidiabetic medications and always take with adequate fluids.

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take three (3) capsules before meals with a full glass of water.

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

See for yourself

Glucomannan by The Vitamin Shoppe label

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

Glucomannan 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 Glucomannan by The Vitamin Shoppe

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container33 Amounts shown are per serving.

Glucomannan

Interacts with
2,022 drugs
1.99 Gram(s) per serving

Glucomannan is a soluble fiber from the konjac root that swells into a gel in your stomach, which may help with mild weight loss, constipation, and mo...

Glucomannan monograph & interactions

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

Interaction report

Glucomannan by The Vitamin Shoppe Drug Interactions

Want to check YOUR meds against Glucomannan?

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
2,022Drugs
2,022 Moderate

Ingredients driving the most interactions

Glucomannan 2,022

Individual Drug Interactions

The ingredients in Glucomannan interact with 2,022 drugs. Click any drug to see the details.

1 of the 1 ingredient in Glucomannan interact with drugs. Each result below shows which ingredient is responsible. Glucomannan

Each ingredient & the kinds of drugs it affects

For each ingredient in Glucomannan 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.

Glucomannan1 drug type · 2,022 drugs

Oral Drugs

Theoretically, glucomannan may decrease absorption of drugs taken orally.
Due to its viscosity and bulking effects, there is concern that glucomannan can decrease the absorption of oral drugs. A small clinical study in healthy volunteers shows that taking glyburide 2.5 mg plus glucomannan 3.9 grams with breakfast reduces plasma levels of glyburide when compared with breakfast and glyburide alone. In addition, animal research demonstrates this effect on amoxicillin, but shows increased absorption of metronidazole. This mouse model also demonstrates that metronidazole elimination is prolonged, but amoxicillin elimination is enhanced by 38%; glucomannan may also affect the distribution of some drugs. To avoid changes in absorption, take glucomannan 30-60 minutes after taking oral drugs.

Likelihood Probable Evidence B
Glucomannan full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Glucomannan, 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

Glucomannan by The Vitamin Shoppe: Common Questions

Does Glucomannan by The Vitamin Shoppe interact with any medications?
Yes. Based on its ingredients, Glucomannan has a known interaction with 2,022 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Glucomannan contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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 glucomannan actually help my constipation or high cholesterol?
Glucomannan has possibly effective evidence for both constipation and high cholesterol. That means it may help, but the evidence isn't rock-solid yet. Your results may vary depending on your dose, how often you take it, and your individual health. Talk with your doctor about whether it's a good fit for what you're trying to manage.
What's the main thing I need to do to take this safely?
Take it with plenty of water — at least a full glass. Glucomannan absorbs water and expands in your throat and digestive tract, so without enough liquid, you risk choking or blockage. Don't swallow it dry or with just a sip.
What side effects should I watch for?
Belly pain, bloating, gas, diarrhea, constipation, nausea, and vomiting are the most common, especially if you take more than 3 grams a day. These usually ease as your body adjusts. Choking or intestinal blockage is rare but serious — call your doctor right away if you have severe chest pain, trouble swallowing, or signs of blockage.
Can I take glucomannan while I'm pregnant?
There isn't enough reliable safety data to say yes or no. Talk with your doctor before using it during pregnancy so you can weigh the benefits and risks for your situation.
How does glucomannan affect my other medications?
Because glucomannan is a thick fiber that expands in your gut, it may slow or reduce how much of an oral medication your body absorbs — including diabetes drugs and many others. Space glucomannan and your medications a couple of hours apart, and check with your doctor or pharmacist about the best timing for your specific drugs.
Is glucomannan the only thing in this capsule?
It's the only active ingredient. The capsule also contains gelatin, rice flour, magnesium stearate, and silicon dioxide — these are inactive fillers and binders that hold the product together.

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

Not sure if Glucomannan is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.

Glucomannan label
Go deeper

The Full Monographs Behind Glucomannan’s Ingredients

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

Herb & supplement monograph

Glucomannan

Interacts with 2,022 drugs

Glucomannan is a soluble fiber from the konjac root that swells into a gel in your stomach, which may help with mild weight loss, constipation, and modestly lowering cholesterol. It is gener...

Read the full Glucomannan monograph →
Sources

Sources & How We Checked

Glucomannan'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 15 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.

Glucomannan 15 references
  1. Henry DA, Mitchell AS, Aylward J, et al. Glucomannan and risk of oesophageal obstruction. Br Med J 1986;292:591-2. PubMed
  2. Shima K, Tanaka A, Ikegami H, et al. Effect of dietary fiber, glucomannan, on absorption of sulfonylurea in man. Horm Metab Res 1983;15:1-3. PubMed
  3. Villaverde, A. F., Benlloch, S., Berenguer, M., Miguel, Rayon J., Pina, R., and Berenguer, J. Acute hepatitis of cholestatic type possibly associated with the use of glucomannan (amorphophalus konjac). J Hepatol. 2004;41(6):1061-1062. PubMed
  4. Yoshida, M., Vanstone, C. A., Parsons, W. D., Zawistowski, J., and Jones, P. J. Effect of plant sterols and glucomannan on lipids in individuals with and without type II diabetes. Eur.J Clin Nutr. 2006;60(4):529-537. PubMed
  5. Wood, R. J., Fernandez, M. L., Sharman, M. J., Silvestre, R., Greene, C. M., Zern, T. L., Shrestha, S., Judelson, D. A., Gomez, A. L., Kraemer, W. J., and Volek, J. S. Effects of a carbohydrate-restricted diet with and without supplemental soluble fiber
  6. Vanderbeek, P. B., Fasano, C., O'Malley, G., and Hornstein, J. Esophageal obstruction from a hygroscopic pharmacobezoar containing glucomannan. Clin Toxicol.(Phila) 2007;45(1):80-82. PubMed
  7. Bernstein, J. A., Crandall, M. S., and Floyd, R. Respiratory sensitization of a food manufacturing worker to konjac glucomannan. J Asthma 2007;44(8):675-680. PubMed
  8. Shichijo, K., Kobayashi, Y., Fueki, R., Shimoyama, K., and Masaya, M. [2 cases of konjac bronchial asthma found outside the "konnyaku" producing district]. Arerugi 1969;18(2):97-100.
  9. Carabin IG, Lyon MR, Wood S, et al. Supplementation of the diet with the functional fiber PolyGlycoplex is well tolerated by healthy subjects in a clinical trial. Nutr J 2009;8:9. PubMed
  10. Lyon MR, Reichert RG. The effect of a novel viscous polysaccharide along with lifestyle changes on short-term weight loss and associated risk factors in overweight and obese adults: an observational retrospective clinical program analysis. Altern Med Rev
  11. Lyon M, Wood S, Pelletier X, et al. Effects of a 3-month supplementation with a novel soluble highly viscous polysaccharide on anthropometry and blood lipids in nondieting overweight or obese adults. J Hum Nutr Diet 2011;24(4):351-9. PubMed
  12. Han Y, Zhang L, Liu XQ, Zhao ZJ, Lv LX. Effect of glucomannan on functional constipation in children: a systematic review and meta-analysis of randomised controlled trials. Asia Pac J Clin Nutr 2017;26(3):471-7.
  13. Health Canada Safety Alert. Health Canada Advises Canadians that natural health products containing glucomannan may cause serious choking if used with insufficient fluid. January 29, 2010. Alert # RA-110003825. https://healthycanadians.gc.ca/recall-alert-
  14. Mortensen A, Aguilar F, Crebelli, et al. EFSA Panel on Food Additives and Nutrient Sources added to Food. Re-evaluation of konjac gum (E 425 i) and konjac glucomannan (E425 ii) as food additives. EFSA Journal 2017;15(6):4864.
  15. Zhang Y, Aldamarany WAS, Song G, et al. Influence of konjac glucomannan and its derivatives on the oral pharmacokinetics of antimicrobial agent in antibiotics cocktails: Keep vigilant on dietary fiber supplement. Int J Biol Macromol 2023;251:126306. PubMed

See these in context on the Glucomannan 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

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team