Health Canada
Symbol of the Government of Canada
Drugs and Health Products

Monograph: Glucomannan - Capsule

This monograph is intended to serve as a guide to industry for the preparation of Product Licence Applications (PLA) and labels for natural health product market authorization. It is not intended to be a comprehensive review of the medicinal ingredient. It is a referenced document to be used as a labelling standard. Note: Text in parentheses is additional optional information which can be included on the PLA and product label at the applicant's discretion. The solidus (/) indicates that the terms are synonyms or that the statements are synonymous. Either term or statement may be selected by the applicant.

Date: 2010-05-10


Glucomannan (ChemIDplus Advanced)

Proper Name(s)

Glucomannan ( NLM 2009 )

Common Name(s)

Glucomannan ( NLM 2009 )

Source Material

Route Of Administration


Dosage Form(s)

Capsules are the only acceptable dosage form.

Use(s) or Purpose(s)

Statement(s) to the effect of:



Cholesterol-lowering products
Dose(s): 1 - 1.5 Grams 3 times per day
Directions For Use:

Laxative; Promote bowel movement; Constipation relief
Dose(s): 0.5 - 5 Grams 3 times per day
Directions For Use:

See Appendix 1 for examples of appropriate dosage preparations and frequencies of use, according to cited references. The purpose of Appendix 1 is to provide guidance to industry.

Duration of use

Cholesterol-lowering products: Consult a healthcare practitioner for use beyond 8 weeks.  (Martino et al. 2005, Walsh et al. 1984)

Risk Information

Statement(s) to the effect of:

Caution(s) and Warning(s):
  • Consult a health care practitioner prior to use if you are pregnant or breastfeeding.
  • Consult a health care practitioner prior to use if you have diabetes.  (Chen et al. 2003, Vuksan et al. 2001)
  • Laxative; Promote bowel movement; Constipation relief:
    Consult a health care practitioner if symptoms worsen or if laxative effect does not occur within 7 days.  (Pray 2006, CPhA 2002)
  • Laxative; Promote bowel movement; Constipation relief:
    Consult a health care practitioner prior to use if you have symptoms such as abdominal pain, nausea, vomiting or fever (as these could be signs of abnormal constrictions of the gastrointestinal tract, diseases of the oesophagus and/or the superior opening of the stomach (cardia), potential or existing intestinal blockage, paralysis of the intestine, megacolon, faecal impaction, inflamed bowel or appendicitis)  (Pray 2006, Berardi et al. 2002)

Do not use if you have difficulty swallowing.  (FDA 2009, Sweetman 2007, Vanderbeek et al. 2007, Henry et al. 1986)

Known Adverse Reaction(s):
  • If you experience chest pain, vomiting, or difficulty swallowing or breathing after taking the product, seek immediate medical attention.  (FDA 2009)
  • Loose stools, flatulence, diarrhea, and abdominal discomfort have been reported.  (Sood et al. 2008)

Non-medicinal ingredients

Must be chosen from the current Natural Health Products Ingredients Database and must meet the limitations outlined in the database.


  • The finished product specifications must be established in accordance with the requirements described in the NHPD Quality of Natural Health Products Guide.
  • The medicinal ingredient must comply with the requirements outlined in the Natural Health Products Ingredient Database (NHPID).

References cited

  • Arvill A, Bodin L. Effect of short-term ingestion of konjac glucomannan on serum cholesterol in healthy men. Am J Clin Nutr. 1995 Mar;61(3):585-9.
  • Berardi RR, DeSimone EM, Newton GD, Oszko MA, Popovich NG, Rollins CJ, Shimp LA, Tietze KJ, editors. Handbook of Nonprescription Drugs: An Interactive Approach to Self-Care, 13th edition. Washington (DC): American Pharmaceutical Association; 2002.
  • Chen HL, Cheng HC, Liu YJ, Liu SY, Wu WT. 2006. Konjac acts as a natural laxative by increasing stool bulk and improving colonic ecology in healthy adults. Nutrition 22:1112-1119.
  • Chen HL, Cheng HC, Wu WT, Liu YJ, Liu SY. 2008. Supplementation of konjac glucomannan into a low-fibre Chinese diet promoted bowel movement and improved colonic ecology in constipated adults: a placebo-controlled, diet controlled trial. Journal of the American College of Nutrition 27:102-108.
  • Chen HL, Sheu WH, Tai TS, Liaw YP, Chen YC. Konjac supplement alleviated hypercholesterolemia and hyperglycemia in type 2 diabetic subjects--a randomized double-blind trial. J Am Coll Nutr. 2003 Feb;22(1):36-42.
  • Chua M, Baldwin TC, Hocking TJ, Chan K. 2010. Traditional uses and potential health benefits of Amorphophallus konjac K. Koch ex N.E.Br. Journal of Ethnopharmacology 128(2):268-278.
  • EFSA 2009: European Food Safety Authority. 2009. EFSA Panel on Dietetic Products, Nutrition and Allergies; Scientific Opinion on the substantiation of health claims related to glucomannan and maintenance of normal blood cholesterol concentrations (ID 836, 1560) pursuant to Article 13(1) of Regulation (EC) No 1924/2006 on request from the European Commission. EFSA Journal 7(9): 1258. doi:10.2903/j.efsa.2009.1258. [Accessed 2009-12-23]. Available from:
  • EMEA 2006. European Medicines Agency. Final Community Herbal Monograph on Plantago afra L. et Plantago indica L., semen. London (UK): EMEA Committee on Herbal Medicinal Products (HMPC), 26 October 2006. [Accessed 2009 November 24]. Available from:
  • FDA 2009: United States Food and Drug Administration. 2009. Specific Labeling Requirements for Specific Drug Products. Code of Federal Regulations Title 21, Volume 4 (21CFR201.319). Rockville (MD): United States Department of Health and Human Services, U.S. Food and Drug Administration. [Accessed 2009-12-23]. Available from:
  • Henry DA, Mitchell AS, Aylward J. Glucomannan and risk of esophageal obstruction. British Medical Journal. 1986 292:591-2.
  • Keithley J, Swanson B, 2005. Glucomannan and obesity: a critical review. Alternative Therapies in Health and Medicine 11:30-34.
  • Loening-Baucke V, Miele E, Staiano A. 2004. Fiber (glucomannan) is beneficial in the treatment of childhood constipation. Pediatrics 113(3 Pt 1):e259-e264.
  • Martino F, Martino E, Morrone F, Carnevali E, Forcone R, Niglio T. Effect of dietary supplementation with glucomannan on plasma total cholesterol and low density lipoprotein cholesterol in hypercholesterolemic children. Nutr Metab Cardiovasc Dis. 2005 Jun;15(3):174-80
  • NLM 2009: United States National Library of Medicine. ChemIDplus advanced [online]. Chemical name. RN: 000-00-0. Bethesda (MD): Specialized Information Services, United States National Library of Medicine, National Institutes of Health, United States Department of Health & Human Services. [Accessed 2009 May 19]. Available from:
  • O'Neil MJ, Smith A, Heckelman PE, Budavari S, editors. 2006. The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 14th edition. Whitehouse Station (NJ): Merck & Co., Inc.
  • Pray WS. Non-Prescription Product Therapeutics, 2nd edition. New York (NY): Lippincott Williams & Wilkins; 2006.
  • Sood N, Baker WL, Coleman CI. 2008. Effect of glucomannan on plasma lipid and glucose concentrations, body weight, and blood pressure: systematic review and meta-analysis. American Journal of Clinical Nutrition 88(4):1167-1175.
  • Sweetman SC , editor. Martindale: The Complete Drug Reference, 35th edition. London (UK): Pharmaceutical Press; 2007.
  • USDA 2003: Germplasm Resources Information Network (GRIN), Amorphophallus konjac K. Koch. United States Department of Agriculture. [Accessed 2009-05-25]. Available from:
  • Vanderbeek PB, Fasano C, O'Malley G, Hornstein J. 2007. Esophageal obstruction from a pharmacobezoar containing glucomannan. Clinical Toxicology 45(1):80-82.
  • Vuksan V, Sievenpiper JL, Xu Z, Wong EYY, Jenkins AL, Beljan-Zdravkovic U, Leiter LA, Josse RG, Stavro M.P. 2001. Konjac-mannan and American ginsing: emerging alternative therapies for type 2 diabetes mellitus. Journal of the American College of Nutrition 20:370S-380S.
  • Walsh DE, Yaghoubian V, Behforooz A. Effect of glucomannan on obese patients: a clinical study. Int J Obes. 1984;8(4):289-93

References reviewed

  • Al-Ghazzewi FH, Khanna S, Tester RF, Piggott J. 2007. The potential use of hydrolysed konjac glucomannan as a prebiotic. Journal of the Science of Food and Agriculture 87:1758-1766.
  • Alonso-Sande M, Teijeiro-Osorio D, Remuñán-López C, Alonso MJ. 2009. Glucomannan, a promising polysaccharide for biopharmaceutical purposes. European Journal of Pharmaceutics and Biopharmaceutics 72:453-462.
  • Australian Competition and Consumer Commission. Commonwealth of Australia Gazette No. S 667, Monday 22 December 1986. Notice of Permanent Ban: Glucomannan in tablet form. Canberra (AU): Australian Government Publishing Service. [Accessed 2009-05-26]. Available from:
  • Birketvedt GS, Shimshi M, Thom E, Florholmen J. Experiences with three different fiber supplements in weight reduction. Med Sci Monit 2005; 11(1): P15-8
  • Chen HL, Fan YH, Chen ME, Chan Y. 2005. Unhydrolyzed and hydrolyzed konjac glucomannans modulated cecal and fecal microflora in Balb/c mice. Nutrition 21:1059-1064.
  • EC-SCF 1997: European Commission 1997 Reports of the Scientific Committee for Food (forty-first series): Opinion on the safety in use of konjac glucomannan as a food additive. Brussels (LU): Office for Official Publications of the European Communities [Accessed 2009-12-23]. Available from:
  • EC-SCF 1997: European Commission 1997. Reports of the Scientific Committee for Food (forty-first series): Opinion on the safety in use of konjac gum as a food additive. Brussels (LU): Office for Official Publications of the European Communities [Accessed 2009-12-23]. Available from:
  • Facciola S. 1998. Cornucopia II: A Source Book of Edible Plants. Vista CA: Kampong Publications.
  • FDA 1993: United States Food and Drug Administration. 1993. 21 CFR Part 201. Warning Statements Required for Over-the-Counter Drugs Containing Water-soluble Gums as Active Ingredients. Final Rule. Federal Register Volume 58, No. 164, August 26, 1993. [Accessed 2009-12-29]. Available from:
  • FDA 1994: United States Food and Drug Administration. 1994. Dietary Supplement Health and Education Act of 1994. [Accessed 2009-12-24]. Available from:
  • HC 1999. Health Canada. 1999. Listing of drugs currently regulated as new drugs. [Accessed 2008-04-11]. Available from:
  • HC 2008: Health Canada. 2008. Drug Product Database [online]. Ottawa (ON): Health Canada. [Accessed 2009 April 17]. Available from:
  • HC 2009: Health Canada. 2009. Canada Vigilance Search REF: 09-137593-955 - Glucomannan.
  • HC 2009: Health Canada. Licensed Natural Health Products Database. [Accessed 2009 December 4]. Available from:
  • JC 2009: Justice Canada 2009. Food and Drugs Act. [Accessed 2009-10-28]. Available from:
  • Livieri C, Novazi F, Lorini R. 1992. The use of highly purified glucomannan-based fibers in childhood obesity. La Pediatria medica e chirurgica 14(2):195-198.
  • Roberts A, O'Brien M, Subak-Sharpe G. 2001. Glucomannan, The Official American Nutraceutical Association Guide, Nutraceuticals The Complete Encyclopedia of Supplements, Herbs, Vitamins, and Healing Foods.
  • Saper RB, Eisenberg DM, Phillips RS. Common dietary supplements for weight loss. Am Fam Physician. 2004 Nov 1;70(9):1731-8.
  • Vasques CAR, Rossetto S, Halmenschlager G, Linden R, Heckler E, Fernandez MSP, Alonso JLL. 2008. Evaluation of the pharmacotherapeutic efficacy of Garcia cambogia plus Amorphophallus konjac for the treatment of obesity. Phototherapy Research 22:1135-1140.
  • Villaverde AF, Benlloch S, Berenguer M, Rayon JM, Pina R, Berenguer J. 2004. Acute hepatitis of cholestatic type possibly associated with the use of glucomannan (Amorphophallus konjac). Journal of Hepatology 41:1061-1067.
  • Vuksan V, Jenkins DJA, Spadafora P, Sievenpiper JL, Owen R, Vidgen E, Brighenti F, Josse R, Leiter LA, Thompson CB. 1999. Konjac-mannan (glucomannan) improves glycemia and other associated risk factors for coronary heart disease in type 2 diabetes. Diabetes Care 22:913-919.
  • Vuksan V, Sievenpiper JL, Owen R, Swilley JA, Spadafora P, Jenkins FJA, Vidgen E, Brighenti F, Josse RG, Leiter LA, Xu Z, Novokmet R. 2000. Beneficial effects of viscous dietary fibre from konjac-mannan in subjects with the insulin resistance syndrome. Diabetes Care 23:9-14.
  • Yoshida M, Vanstone CA, Parsons WD, Zawistowski J, Jones PJ. Effect of plant sterols and glucomannan on lipids in individuals with and without type II diabetes. Eur J Clin Nutr. 2006 Apr;60(4):529-37

Appendix 1: Examples of appropriate dosage preparations, frequencies of use and directions for use

Cholesterol-lowering studies:

  • 0.43 g glucomannan/capsule: Three capsules taken three times daily with a glass of water one-half hour before meals [total daily amount 3.87 g glucomannan] for four weeks (Arvill et al. 1995)
  • 0.5 g konjac powder/capsule taken three times daily, one half hour before each meal with a glass of water. The dose of glucomannan fiber increased progressively from 1.2 (for 3 days), 2.6 (for 3 days), to 3.6 g per day for 22 days (Chen et al. 2003)
  • 4 g/d of glucomannan in one or more servings (EFSA 2009)
  • 0.5 g glucomannan/capsule. Children aged up to 6 years: received 2 capsules at lunch and 2 at dinner [total daily amount 2 g]; whereas, Children aged over 6 years: received 3 capsules at lunch and 3 at dinner [total daily amount 3 g]. Four week treatment period. (Martino et al. 2005)
  • 500 mg glucomannan/capsule: Two capsules three times per day with 8 oz water, one hour before each meal [total daily amount 3 g glucomannan] for eight weeks (Walsh et al. 1984)

Laxative products:

  • 500 mg glucomannan/capsule: Capsule taken with 150 mL water during each meal. The dose increased during the adaptation period from 1.5 g/d (days 1-3) to 3.0 g/d (days 4-7) and was maintained at 4.5 g/d during the treatment period of 21 days (Chen et al. 2008; Chen et al. 2006)
  • 2-3 g glucomannan per day from ten days to three months (González Canga et al. 2004)

Children 7 years and older:

500 mg glucomannan/capsule: Each capsule was either opened and sprinkled on food given with 50 mL of fluid per capsule; given as a solution, whereby the content of each capsule was mixed with 50 mL of fluid of the child's choice; or swallowed as a capsule with 50 mL of fluid for each capsule. Given as 100 mg/kg body weight daily (maximal 5 g/day) for four weeks (Loening-Baucke et al. 2004)