Ingredient · Updated 2026-08-17
Glucomannan
Amorphophallus konjac fibre
Grade B for weight management when you actually take ~3 g/day with water before meals as part of an energy-restricted diet. Capsules that hide 500 mg in a blend are not that protocol. Take it with enough water; it swells.
- Study-dose band
- ~3 g/day, divided, with plenty of water
- Typical bottle
- 500–3,000 mg; many fat-burner blends are far below 3 g
Evidence by outcome
| Outcome | Grade | Note |
|---|---|---|
| Weight in a calorie deficit | B | EFSA authorised a claim for glucomannan and weight loss in the context of an energy-restricted diet at 3 g/day. |
| LDL cholesterol | B | Viscous fibre mechanism is plausible and reasonably replicated. |
Safety
- Choking and obstruction risk if swallowed dry. Always with a full glass of water.
- Can reduce absorption of some medicines; separate by a couple of hours.
Unknowns
- Capsule vs powder: you need the grams, not the botanical name.
Questions
Is glucomannan a fat burner?
No. It is a viscous fibre that can increase satiety. The authorised claim is tied to 3 g/day plus an energy-restricted diet.