✓ No active regulatory warningsFDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
📰Read the full Glucomannan evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ CHOKING HAZARD — never take dry. Always 240+ mL water per dose [2]
⚠ EFSA-authorized weight loss claim — rare for a supplement [1]
⚠ Banned as tablets in Australia [2]
⚠ Separate ALL medications by 1+ hours [1]
ℹ️ Not obtained from food. Not applicable — this is not obtained from food in meaningful amounts; supplementation is the practical route.
🔬 Lab interpreter
ℹ️ No validated blood test. There is no established laboratory test to assess status or guide dosing for this ingredient. Clinical response and symptoms are the practical guide.
⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
Glucomannan has one of the ONLY EFSA-authorized weight loss claims (≥3 g/day + caloric restriction). Absorbs 50× its weight in water. ~0.8 kg/5 weeks (modest). CHOKING HAZARD is real — tablets BANNED in Australia. ALWAYS take with 240+ mL water. Shirataki noodles = food form (no choking risk) [1] [2].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
Fiber. Generally safe with adequate water [1].
👦 Pediatric: See guidance
Choking hazard concern — use with caution [2].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: 30 min before meals with 240+ mL water [1].
💊 With food: BEFORE meals with WATER — the satiety mechanism [1].
🚫 Avoid: Taking without water (CHOKING). Lying down after taking [2].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Glucomannan capsules/powder', 'common', '1 g per dose. MUST take with large glass of water [1].'] | Standard | Check label | |
| ['Konjac noodles (shirataki)', '', 'Food form. Nearly zero calories. Popular in Japan and low-carb diets [1].'] | Standard | Check label |
3 Common questions
Is the EFSA weight loss claim significant? ▼
EFSA rarely approves weight loss claims — glucomannan is one of the few. ~0.8 kg over 5 weeks is modest but the mechanism (satiety from viscous gel) is sound. Must be combined with caloric restriction [1].
Choking risk — how serious? ▼
Serious enough that glucomannan tablets are BANNED in Australia. The fiber expands rapidly — dry tablets can obstruct the esophagus. ALWAYS take with large glass of water. Never take lying down [2].
Shirataki noodles? ▼
Konjac-based noodles with nearly zero calories. Popular in Japan and low-carb diets. Provides glucomannan in food form (no choking risk). Rubbery texture — rinse well before cooking [1].
4 Clinical evidence
Strong
EFSA authorized health claim for weight loss (≥3 g/day) — one of very few supplement weight loss claims authorized by a regulatory body [1]. Extreme viscosity: 50× water absorption — established [1]. Choking hazard from dry formulations — documented cases [2]. HIGH
Moderate
Weight loss: meta-analysis showed ~0.8 kg over 5 weeks (modest but consistent) [1]. Cholesterol: modest LDL reduction [1]. Blood glucose: reduced postprandial glucose (viscous fiber effect) [1]. Constipation: improved bowel frequency [1]. MODERATE
Insufficient
5 Safety, toxicity & adverse events
Absolute contraindications
✕ Difficulty swallowing or esophageal/GI narrowing — choking and obstruction risk
Relative
⚠ Must be taken with ample water and not immediately before lying down
⚠ Separate from medications by ~2 hours (reduces absorption)
⚠ Diabetes — additive glucose lowering
🚩 Red flags
● Patient taking glucomannan tablets without adequate water [2]
● Dysphagia patient — contraindicated [2]
● GI stricture patient — contraindicated [2]
6 Interactions
Drug interactions
ALL oral medications Moderate
Mechanism: Viscous gel matrix delays drug absorption. [1]
Effect: Reduced drug bioavailability. [1]
Action: Separate by 1+ hours [1].
Supplement synergies
Chromium · 200 µg chromium picolinate
Both support glucose management [1].
Both support glucose management [1].
7 Regulatory
EFSA: Authorized health claim: weight loss at ≥3 g/day [1].
Australia: Glucomannan TABLETS banned due to choking hazard [2].
United States: Dietary supplement [1].
8 US supplement products
75
on-market products containing Glucomannan (NIH DSLD)
Brands carrying Glucomannan (43)
Click a brand to see its Glucomannan products.
9 Frequently paired with
10 Cite this page
Vancouver: Pkhakadze G. Glucomannan — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Jul 17]. Available from: https://supplement.ge/ingredients/glucomannan/
APA 7th: Pkhakadze, G. (2026). Glucomannan — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/glucomannan/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: January 2027
References: 2 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "Glucomannan — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/glucomannan/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG