Glucomannan is used for constipation, diabetes, and high cholesterol. Some people take glucomannan by mouth for high blood pressure, obesity, and other conditions, but there is no good scientific evidence to support these other uses of glucomannan.
In foods, glucomannan is used as a thickener or gelling agent. It is also included in food as a dietary fiber.
Uses & Effectiveness ?
Possibly Effective for
- Constipation. Taking glucomannan by mouth can relieve constipation in adults. It might also reduce constipation in children, but results are mixed.
- Diabetes. Taking glucomannan by mouth seems to reduce cholesterol, blood sugar levels, and blood pressure in people with diabetes.
- High cholesterol. Taking glucomannan by mouth seems to improve cholesterol levels in people with or without high cholesterol.
Insufficient Evidence for
- Rapid gastric emptying (dumping syndrome). Dumping syndrome occurs when food moves from the stomach to the intestines too quickly. This can cause the body to release a large amount of insulin, which can cause low blood sugar. Some early research shows that taking glucomannan by mouth helps prevent blood sugar from becoming too low after eating in people at risk for this condition. However, not all research agrees.
- High blood pressure. Early research shows that glucomannan might improve blood pressure in people with high blood pressure.
- Overactive thyroid (hyperthyroidism). Early research shows that adding glucomannan to treatment with methimazole and propranolol helps to reduce thyroid hormone levels in people with overactive thyroid.
- Obesity. Some early research shows that taking glucomannan by mouth improves weight loss in overweight and obese adults and children. However, not all research agrees.
- Disorders marked by persistent and recurring GI symptoms (functional gastrointestinal disorders).
- Other conditions.
Special Precautions and Warnings
Children: Glucomannan powder and capsules are POSSIBLY SAFE for most children when used as medicine, short-term. But solid tablets containing glucomannan are LIKELY UNSAFE. These tablets may cause blockages of the throat or intestines.
Medications for diabetes (Antidiabetes drugs) interacts with GLUCOMANNAN
Glucomannan can decrease blood sugar in people with type 2 diabetes. Diabetes medications are also used to lower blood sugar. Taking glucomannan along with diabetes medications might cause your blood sugar to go too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.
Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.
Medications taken by mouth (Oral drugs) interacts with GLUCOMANNAN
Glucomannan absorbs substances in the stomach and intestines. Taking glucomannan along with medications taken by mouth can decrease how much medicine your body absorbs, and decrease the effectiveness of your medication. To prevent this interaction, take glucomannan at least one hour after medications you take by mouth.
Be cautious with this combination
- For constipation: 2-4.5 grams per day, taken in single or split doses, for up to 12 weeks.
- For high cholesterol: Various glucomannan doses and dosage forms have been used for up to 12 weeks. These include eating biscuits containing 0.5-0.7 grams of glucomannan per 100 kcal, taking 2.4-3.9 grams of glucomannan supplements daily, eating bars containing 3.33 grams of glucomannan three times daily, or eating foods containing 5-10 grams of glucomannan daily.
- For diabetes: 3-4 grams per day for up to 8 weeks. Eating biscuits containing 0.5-0.7 grams of glucomannan per 100 kcal has also been used for 3 weeks. A specific supplement providing 2.5-7.5 grams of glucomannan has also been used with meals.
- For constipation: Up to 5 grams in single doses or split doses daily for 4-12 weeks.
- For high cholesterol: 2-3 grams in single doses or split doses daily for 8 weeks.
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