Glucomannan is a sugar produced from the root of Amorphophallus konjac (konjac plant). Glucommanan capsules, powder, and tablets are used in medicine. This plant seems to be effective against constipation, type 2 diabetes, weight loss in grown-ups and children, blood sugar control, and decreasing cholesterol. Glucomannan is known as a gelling agent or a thickener.
Glucomannan works in the intestines and stomach by absorbing water forming a bulky fiber. This very fiber is effective in treatment of constipation. It also slows the cholesterol and sugar absorption from the gut, controlling sugar levels in patients suffering from diabetes, and decreasing cholesterol levels
According to the scientific research, Glucomannan is possibly effective for decreasing cholesterol levels in patients with diabetes and assisting to control blood sugar in patients with type 2 diabetes. There is insufficient evidence for the effectiveness of Glucomannan in treatment of weight loss, constipation, high cholesterol (in combination with chitosan) and some other conditions.

Glucomannan originates from subtropical Asian regions and is also known as konjaku, konjak, and konnyaku potato. Due to its ability to swell and absorb water glucomannan is used as a weight loss supplement that suppresses appetite by expanding within the stomach and giving the feeling of fullness.
Some studies have been made on glucomannan and proved this component to be effective in weight loss for obese people. Glucomannan capsules and powder are safe for most grown-ups and children. Solid tablets with glucomannan may be unsafe. They can cause blockages of intestines or the throat, more read at florastor.
Special precautions should be taken by pregnant and breast-feeding women as very little is known about the use of glucomannan in these periods of women's life. So, it's better to stay on the safe side.
Glucomannan has to be carefully used by people with diabetes. This component may influence the blood sugar level. So, this index should be regularly monitored if a person diabetes and takes glucomannan. This ingredient may also interfere with the level of blood sugar during and after surgery. Glucomannan is prohibited for usage minimum 2 weeks before a surgery.