Supplement Scholar
Compound

Glucomannan (Konjac)

Buy on Amazon ↗

Affiliate link: we may earn a commission at no extra cost to you. Disclosures

Glucomannan (Konjac). Viscous soluble fiber that promotes satiety and lowers LDL.

How it works. Expands in stomach to slow gastric emptying; binds bile acids.

What the research supports. 2 graded claims. Strongest: Lowers LDL ~10% (strong).

How much to take. Typical dose: 1 g tid with 250 mL water.

Side effects and interactions. 1 medication interaction listed. Serious: Esophageal obstruction if not taken with water.

Stacking. Pairs well with A high-quality multivitamin, Omega-3 (EPA/DHA).

Common forms. Available as Capsule or softgel, Powder, Sublingual or buccal, Liposomal liquid.

Key studies. 9 studies cited. The strongest are listed with links to PubMed.

Community. Experiences from people who have tried Glucomannan (Konjac). Anecdotes are not medical advice.

Glucomannan (Konjac). Viscous soluble fiber that promotes satiety and lowers LDL.

Molecular structureC24H42O21 · 666.6 g/mol

What it is

Viscous soluble fiber that promotes satiety and lowers LDL.

Food sources

Endogenously produced or biosynthesized moleculeStandardized pharmaceutical- or food-grade supplementCombined with cofactors that improve absorption or activity

Goals

Blood Sugar Management

How it works

Expands in stomach to slow gastric emptying; binds bile acids.

Pathways

  • Expands in stomach to slow gastric emptying
  • binds bile acids

Effects

  • +Modest weight loss as part of hypocaloric diet supports
  • ↓LDL ~10% decreases

What the research supports

Lowers LDL ~10%strong
Modest weight loss as part of hypocaloric dietmoderate

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Typical dose
1 g tid with 250 mL water
TimingConsistent daily timing recommended; split larger doses if GI tolerance is a concern.
With foodBefore meals
Best formMost evidence is based on the capsule or softgel form.
Shop Glucomannan (Konjac) on Amazon ↗

As an Amazon Associate I earn from qualifying purchases. Look for USP, NSF or Informed Sport seals before you buy.

Side effects & interactions

Common side effects

  • Bloating
  • Choking risk if dry

Serious

  • Esophageal obstruction if not taken with water

Medication interactions

Oral medicationsmoderate

Take 1 h apart due to absorption interference.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • A high-quality multivitaminCovers micronutrient cofactors that support most supplement pathways.
  • Omega-3 (EPA/DHA)Foundational anti-inflammatory support that complements most regimens.

Common forms

  • Capsule or softgel
  • Powder
  • Sublingual or buccal
  • Liposomal liquid

Key studies

9 studies cited in total.

PubMed: Glucomannan (Konjac) — Modest weight loss as part of hypocaloric diet ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Glucomannan (Konjac) and "Modest weight loss as part of hypocaloric diet". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Glucomannan (Konjac) — Lowers LDL ~10% ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Glucomannan (Konjac) and "Lowers LDL ~10%". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Glucomannan (Konjac) — randomized controlled trial ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Glucomannan (Konjac) and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

Discussion

Loading discussion…