Glucomannan is a dietary fiber. It is usually made from the root of the konjac plant. Glucommanan powder, capsules, and tablets are used as medicine.
Orally, glucomannan is used for constipation, weight loss, diabetes, high cholesterol, overactive thyroid (hyperthyroidism), high blood pressure, and stomach conditions called dumping syndrome and functional gastrointestinal disorder.
In foods, glucomannan is used as a thickener or gelling agent. Glucommanan flour and powder are used in food.