botanical Botanicals Oral

Glucomannan

A highly viscous soluble fiber from konjac root, used primarily for appetite control and supporting healthy cholesterol and blood sugar levels.

Sci.Amorphophallus konjac glucomannan glycerite liquid extract glucomannan, powder konjac luralean propolmannan konjac mannan luralean propolmannan
3 forms
Oral

About Glucomannan

Glucomannan is a water-soluble, fermentable dietary fiber polysaccharide composed of β-1,4-linked D-mannose and D-glucose units, derived primarily from the root of the konjac plant (Amorphophallus konjac). It is a high-molecular-weight, highly viscous fiber that forms a gel in the gastrointestinal tract, contributing to its primary mechanisms of action related to appetite, glycemic control, and cholesterol modulation.

Official resources

Fact sheets from the NIH Office of Dietary Supplements related to this ingredient group.

Dietary Supplement Label Database

Ingredient group data in NutriNav is aligned with the NIH Dietary Supplement Label Database (DSLD).

DSLD group id
269

At a glance

Suggested daily

No established RDA. For weight management support, clinical studies often use 3-4 grams per day, taken with water before meals.

Max safe daily

No established UL. High doses (>15g/day) may cause gastrointestinal discomfort, obstruction, or interfere with medication absorption.

Approval status

GRAS (Generally Recognized as Safe) as a dietary fiber for specific food uses; also marketed as a dietary supplement.

Compare All Forms

3 forms

Compare supplement forms of Glucomannan by absorption quality and what your body actually gets from each:

High Moderate Low
Form Absorption Steps to absorb Notes Action
Glucomannan

Take with plenty of water before meals. May cause bloating.

  • UNII: 9V7B5E7314
  • CAS: 37220-17-0
  • Label category: Natural (Konjac)
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Konjac Flour

A soluble fiber from konjac root. Promotes satiety and diges...

  • UNII: 5C69LZ8B3L
  • CAS: 37220-17-0
  • Label category: natural
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Konjac Glucomannan Gel

A highly absorbent, soluble fiber gel from konjac root. Prom...

  • CAS: 37220-17-0 (for glucomannan)
  • Label category: natural
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Also appears on labels as

Additional names seen on supplement labels for forms of this ingredient (beyond the main aliases above).

E425 (food additive), Elephant yam flour, Elephant yam gel, Glucomannan, Glucomannan hydrogel, Konjac Fiber, Konjac flour gel, Konjac Glucomannan, Konjac gum, Konjac mannan gel, Konjac root flour, Konjac root gel

Type: Botanicals

Category for Botanicals ingredients

Watch out for

Possible interactions or cautions — talk to a healthcare provider if unsure.

  • May reduce absorption of oral medications (e.g., diabetes drugs, cholesterol-lowering drugs, sulfonylureas) if taken simultaneously. Separate administration by several hours.

Potential Benefits

Benefits associated with Glucomannan forms:

Cholesterol Reduction Satiety Blood Sugar Regulation Weight Management / Appetite Suppression Relief of Constipation Blood Sugar Modulation

And 4 more benefits...

Potential Side Effects

Side effects associated with Glucomannan forms:

Bloating How serious: Mild Choking Risk (dry) How serious: High Gastrointestinal Discomfort How serious: low Esophageal or Intestinal Blockage How serious: high Interference with Medication Absorption How serious: medium Allergic Reaction (rare) How serious: Moderate

What does the research say?

A substantial body of clinical research exists for glucomannan, primarily focused on its effects on weight management, cholesterol, and glycemic control. Meta-analyses and systematic reviews (e.g., 2018 review on obesity) suggest a modest but statistically significant effect on weight loss and reduction of LDL cholesterol when taken before meals, attributed to its high viscosity and bulking properties that promote satiety and interfere with fat/glucose absorption. Evidence for constipation relief is strong, as it is a well-established soluble fiber. Its use in topical applications is supported more by its physical and rheological properties than by specific clinical trials for skin benefits.