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Dietary supplement

High Strength Glucomannan Fibre 500 mg Ingredients & Drug Interactions

by Simply Supplements

High Strength Glucomannan Fibre 500 mg label
See full label image
Capsule Category: Fiber And Other 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 High Strength Glucomannan Fibre 500 mg 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

High Strength Glucomannan Fibre 500 mg is a dietary supplement by Simply Supplements 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.

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Check Your Meds Against High Strength Glucomannan Fibre 500 mg by Simply Supplements

Ask about any prescription or over-the-counter medication and we check it for interactions with High Strength Glucomannan Fibre 500 mg by Simply Supplements — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of High Strength Glucomannan Fibre 500 mg by Simply Supplements

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 6, 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 a single active ingredient: glucomannan, a soluble fiber derived from the konjac plant root. At 500 mg per capsule, it's designed to add bulk and water-holding capacity to your stool.

The inactive ingredients are microcrystalline cellulose (a binder), the capsule shell itself, and a color additive — all standard capsule components.

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: weight loss and blood cholesterol support.
  • We looked for evidence on: Obesity, Hyperlipidemia, Weight management, Cholesterol management.
  • The strongest evidence on file: Glucomannan is rated "Possibly Effective" for Hyperlipidemia (Natural Medicines).
  • Also on file: Glucomannan is rated "Insufficient Reliable Evidence To Rate" for Obesity.

The evidence behind glucomannan is mixed. It's rated possibly effective for constipation, for type 2 diabetes management, and for high cholesterol (hyperlipidemia).

For high blood pressure (hypertension), there isn't enough reliable evidence to say whether it works. If you're considering this for one of those conditions, talk with your doctor about whether it fits into your overall plan — a fiber supplement is usually a piece of a bigger picture, not a replacement for other treatments.

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.

Glucomannan is generally well tolerated when you take it with plenty of water or liquid — that's the key safety point. The most common side effects are mild digestive complaints: bloating, gas, constipation, diarrhea, nausea, or abdominal pain, especially at higher doses.

Rare but serious side effects include choking or blockage in your throat or gut, particularly if you swallow the powder dry or don't drink enough liquid with it. For pregnancy, there isn't enough reliable safety data — talk with your doctor before using it during pregnancy.

For breastfeeding, safety data is scarce, so caution is advised and a conversation with your doctor or pharmacist is wise.

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 taking this product, check with your doctor or pharmacist about any oral medications you're on — any drug you swallow by mouth could potentially be affected. The concern is Moderate: glucomannan may lower how much of your medication your body absorbs, which could make it less effective.

Spacing your medications 2 hours away from the supplement is often recommended, but your healthcare provider needs to assess your specific drugs and decide whether that's enough.

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.

If you deal with constipation and need extra fiber, or if your doctor has mentioned it for blood sugar or cholesterol support, this could be worth a try — as long as you're diligent about drinking plenty of water with it and you're not taking oral medications that could be affected. Because glucomannan can interfere with medication absorption, check your exact prescription drugs with your doctor or pharmacist before you start.

This is a low-risk product on its own, but it needs careful timing around your other healthcare.

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 Mar 24, 2017.

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 High Strength Glucomannan Fibre 500 mg, straight from the product label.

Brand Simply Supplements
Barcode (UPC) 5060370564224
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Mar 24, 2017
DSLD ID 70691
Product type Fiber And Other Nutrients
Supplement form Capsule
Dietary claims / uses Nutrient, All Other
Intended target group(s) Vegetarian, 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 High Strength Glucomannan Fibre 500 mg by Simply Supplements, 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:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
UPC/BARCODE
5060370564224
IngredientAmount% DV
Glucomannan1000 mg--

Other ingredients: Microcrystalline Cellulose, Capsule Shell, Colour

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

Same day Despatch We will ensure your order is despatched on the day of receipt (when placed before 12.30pm) and that all orders placed after 12.30pm are despatched on the next working day. All sent 1st class!

PriceMatch guarantee! If you buy from us and then see the same product cheaper elsewhere we will refund the difference plus 10%!

Proven to support weight loss

EasyGest Capsules Easy to swallow Easy to absorb Easy to digest No product odour No bad taste

Image is for illustration purposes only.

Formula

High Strength Glucomannan Fibre 500 mg

Product information Glucomannan (Konjac fibre) has been proven to support weight loss as part of a calorie controlled diet, and contributes to the maintenance of normal blood cholesterol levels.

Seals/Symbols

Quality Assured

V Vegetarian

Suggested/Recommended/Usage/Directions

Suggested daily intake: Take two capsules daily as a food supplement or as directed by a healthcare professional.

Precautions

Important information If you are taking any prescription medication, you have a medical condition or you have specific concerns about the suitability of our products, always consult your GP or Pharmacist prior to taking supplements.

Do not exceed stated dose.

Keep away from children at all times.

Do not use if seal is broken.

Pregnant or lactating women should consult a Doctor before using this product.

Food supplement: This product should not be used as a substitute for a varied diet.

Storage

Store in a cool dry place.

Formulation

Suitable for Vegetarians.

General

E583

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

See for yourself

High Strength Glucomannan Fibre 500 mg by Simply Supplements label

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

High Strength Glucomannan Fibre 500 mg 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 High Strength Glucomannan Fibre 500 mg by Simply Supplements

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

Serving size2 Capsule(s) Dosage formCapsule Amounts shown are per serving.

Glucomannan

Interacts with
2,022 drugs
1000 mg per serving Form: Amorphallus konjac

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: Microcrystalline Cellulose, Capsule Shell, Colour. These complete the product’s ingredient list but are not active constituents.

Interaction report

High Strength Glucomannan Fibre 500 mg by Simply Supplements Drug Interactions

Want to check YOUR meds against High Strength Glucomannan Fibre 500 mg?

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 High Strength Glucomannan Fibre 500 mg interact with 2,022 drugs. Click any drug to see the details.

1 of the 1 ingredient in High Strength Glucomannan Fibre 500 mg interact with drugs. Each result below shows which ingredient is responsible. Glucomannan

Each ingredient & the kinds of drugs it affects

For each ingredient in High Strength Glucomannan Fibre 500 mg 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 High Strength Glucomannan Fibre 500 mg, from the product label.

Simply Supplements

See all Simply Supplements products
Name
Simply Supplements
Street Address
PO Box 1330
City
Peterborough
ZipCode
PE2 2PW
Phone Number
0800 988 0292
Pharmacist Counseling Corner

High Strength Glucomannan Fibre 500 mg by Simply Supplements: Common Questions

Does High Strength Glucomannan Fibre 500 mg by Simply Supplements interact with any medications?
Yes. Based on its ingredients, High Strength Glucomannan Fibre 500 mg 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?
High Strength Glucomannan Fibre 500 mg 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.
How much water should I drink with this?
The product label emphasizes taking it with plenty of water. Glucomannan absorbs water and expands in your digestive tract, so swallowing it dry or without enough liquid puts you at real risk of choking or blockage — especially serious in your throat or gut. Drink a full glass of water (or more) every time you take it.
Can I take this with my other medications?
Not without checking first. Glucomannan may reduce how well your body absorbs oral drugs, which could make them less effective. Talk with your doctor or pharmacist about the medications you take and whether you can safely time them 2 hours apart from this supplement, or whether it's not a fit for you right now.
Is it safe to take during pregnancy?
There isn't enough reliable safety data to say either way. Before taking this during pregnancy, talk with your doctor — you need personalized advice based on your own health situation.
What are the most common side effects?
Bloating, gas, constipation, diarrhea, nausea, and belly pain are the typical complaints, especially if you take more than 3 grams a day or don't drink enough liquid with it. These usually ease as your body adjusts. Serious side effects like choking or blockage are rare but happen when glucomannan is swallowed dry or without plenty of water.
Does this actually work for constipation?
The evidence says it's possibly effective. Glucomannan is a soluble fiber, so it adds bulk and water to stool, which should help you go more regularly — but results vary person to person, and you have to drink plenty of water for it to work properly.
Can I take this while breastfeeding?
Safety data is limited, so caution is advised. Talk with your doctor or pharmacist before using it while breastfeeding to make sure it's right for your situation.

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

Not sure if High Strength Glucomannan Fibre 500 mg is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

High Strength Glucomannan Fibre 500 mg label
Go deeper

The Full Monographs Behind High Strength Glucomannan Fibre 500 mg’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

High Strength Glucomannan Fibre 500 mg'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

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