What is it used for?
Helps to lower cholesterol levels (by reducing cholesterol absorption from the gastrointestinal tract) [Source note 2].
(Used in Herbal Medicine as a) bulk-forming laxative [Source note 3].
(Used in Herbal Medicine to) promote(s) bowel movements (by increasing bulk volume and water content) [Source note 4].
(Used in Herbal Medicine to) provide(s) gentle relief of constipation and/or irregularity [Source note 5].
Note: The above uses can be combined on the product label if from the same system of medicine (e.g. Used in Herbal Medicine as a bulk-forming laxative for gentle relief of constipation and/or irregularity).
What this guide covers
this reference is intended to serve as a guide to industry for the preparation of product documentation and labels for supplement market authorization.
Who does this guide cover?
Adults 18 years and older
How is it taken?
Oral
Which forms are covered?
this reference excludes foods or food-like dosage forms as indicated in the Compendium of references Guidance Document.
The acceptable dosage forms are limited to the oral capsule and powder dosage forms listed in the dosage form drop-down list of the source’s list of accepted product forms.
Quantities
Lowering of cholesterol
1 - 1.5 grams of glucomannan, 3 times per day [Source note 6]
Laxative; Promotion of bowel movement; Constipation relief
0.5 - 5 grams of glucomannan, 3 times per day [Source note 7]
How is it used?
All products
For each dose, drink at least 250 ml of liquid (FDA 2023, Martino et al. 2005, Chen et al. 2003, Arvill and Bodin 1995, Walsh et al. 1984).
Maintain adequate fluid intake [Source note 8].
Take a few hours before or after taking other medications or health products [Source note 9].
Taking this product with insufficient liquid may result in choking, or blockage/obstruction of the throat, esophagus or intestine [Source note 10].
For powder dosage forms
Mix well with liquid and drink immediately.
Lowering of cholesterol
Take 0.5-1 hour before meals [Source note 11].
Laxative; Promotion of bowel movement; Constipation relief
Effects observed 12-24 hours after first dose, but may take 2-3 days [Source note 12].
Optional
Take during the day (not immediately prior to bedtime) [Source note 13].
Optional (for products with a dosage range)
Minimum daily dose may be increased, up to the maximum daily dose, until desired effect is obtained.
How long is it used?
Cholesterol-lowering products
Ask a healthcare practitioner/healthcare professional for use beyond 8 weeks [Source note 14].
Warnings and precautions
All products
Ask a healthcare professional immediately if you experience chest pain, vomiting, or difficulty swallowing or breathing after taking this product [Source note 15].
Ask a healthcare professional before use if you are pregnant or breastfeeding.
Ask a healthcare professional before use if you have diabetes or a lazy bowel [Source note 16].
Laxative; Promotion of bowel movement; Constipation relief
Ask a healthcare professional if symptoms worsen or if laxative effect does not occur within 7 days [Source note 17].
When should it be avoided?
All products
Do not use if you have difficulty swallowing [Source note 18].
Do not use if you have fever or any undiagnosed gastrointestinal trouble [Source note 19].
Possible side effects
All products
Stop use if hypersensitivity/allergy occurs [Source note 20].
When using this product you may experience temporary gas and bloating [Source note 21].
Storage
Must be established in accordance with the requirements described in the applicable product regulations.
Preparation details
Ingredient identity, preparation requirements, and other details that define the scope of this guide.
Ingredients and preparations
| Proper name(s) | Common name(s) | Source information / Source material(s) | Source information / Part(s) |
|---|---|---|---|
| Glucomannan | Glucomannan |
| Tuber |
References: Proper name: NIH 2023, RSC 2023; Common names: NIH 2023, Chua et al. 2010, RSC 2023; Source information: USDA 2023, RSC 2023.
Other ingredients
Must be chosen from the current source ingredient database and must meet the limitations outlined in the database.
Preparation and quality requirements
The finished product specifications must be established in accordance with the requirements described in the source authority source’s product quality guidance.
The active ingredient must comply with the requirements outlined in the source ingredient database.
Guide change history
Updates to this SupplementSafety.org guide.
Minor updates
Updated guide wording, organization, and source presentation. Added our editorial change history.
Initial release
Initial SupplementSafety.org guide prepared from source reference material.
Validation: Not yet completed. Editorial updates do not constitute clinical validation.
Sources
Source information
This guide organizes source material about uses, preparations, amounts, and precautions. Read the conditions alongside each statement; the information may apply only to particular preparations or populations.
The source document includes supporting references. We have not independently summarized or assessed every cited study for this guide.
- Source document version
- July 26, 2024
- Source captured
- Aug 15, 2026
- Editorial work
- Editorial preparation. Independent clinical review has not been recorded for this guide.
Full citations are available through the link above. Verification is required to open them; reading this guide does not require verification.
Taking a medication too?
Explore our supplement–medication interaction checker. Its coverage and review status are shown with the results; a missing finding does not establish that a combination is safe.