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Konjac glucomannan

EFSA-authorised soluble fibre for cholesterol reduction and for weight loss in the context of an energy-restricted diet.

Why

Glucomannan (from the konjac root, Amorphophallus konjac) is a highly viscous soluble fibre with two EFSA-authorised health claims, for the maintenance of normal blood cholesterol (≥4 g/day) and for weight loss in the context of an energy-restricted diet (≥3 g/day before meals). Effect on LDL is modest but consistent; weight-loss effect is small in absolute terms but EFSA-recognised.

How it works

Absorbs water in the stomach to form a viscous gel, slowing gastric emptying and promoting satiety, basis of the weight-loss claim. In the small intestine, binds bile acids and slows nutrient absorption, basis of the cholesterol claim.

Expected onset · Satiety acute; LDL changes over 4–6 weeks

How to take

Dosage

LDL reduction: 4 g/day, split. Weight loss: 1 g three times daily with at least 1–2 glasses of water, taken 15–30 min before meals.

Timing

Before meals, with substantial water

On the label

Powder or capsules (not pre-formed tablets), pre-formed tablets carry choking risk. Stated glucomannan content per dose.

Ideal for

Adults with mild dyslipidaemia or seeking adjunct satiety support during weight loss; people with constipation looking for a soluble fibre option distinct from psyllium.

Safety

**Always with abundant water, choking and oesophageal obstruction are documented with tablets that swell in the throat**. Glucomannan tablets that pre-swell before swallowing are particularly risky. Can reduce absorption of co-administered medications. Separate by 2–4 hours. Mild GI upset (bloating, flatulence). Avoid in oesophageal stricture or known dysphagia.

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Evidence

At a glance

EFSA authorised both the cholesterol claim (≥4 g/day) and the weight-loss claim (≥3 g/day in energy-restricted context). Sood 2008 Am J Clin Nutr meta-analysis: glucomannan reduced total cholesterol by 0.5 mmol/L and LDL by 0.4 mmol/L vs control. Weight effect is modest but real, clinical magnitude smaller than EFSA authorisation alone suggests.

Where to get it

Shop Konjac glucomannan on Amazon

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