Glucomannan Benefits and Uses

Shirataki noodles, peas, asparagus, star-shaped tofu
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Glucomannan is a substance extracted from the root of the konjac (a plant native to Asia). Glucomannan is rich in soluble fiber, the type of dietary fiber that attracts water and turns to gel during digestion. Long used in traditional Chinese medicine (a form of alternative medicine that originated in China), glucomannan is now sold as a dietary supplement and weight loss aid.


In alternative medicine, glucomannan has a long history of use as a detox aid and treatment for asthma, cough, and skin disorders. Today, many proponents claim that glucomannan may help with the following conditions:

In addition, glucomannan is purported to promote weight loss and slow the aging process. Some proponents suggest that glucomannan can also improve thyroid health and even fight some forms of cancer (such as lung cancer).

Health Benefits

Although research on the health effects of glucomannan is somewhat limited, several studies suggest that glucomannan may offer certain health benefits. Here's a look at some key findings from the available research:

1) Weight Loss

In a research review published in Alternative Therapies in Health and Medicine in 2005, scientists found that taking glucomannan in doses of two to four grams per day may result in significant weight loss among overweight and obese individuals. According to the review's authors, glucomannan may help promote weight loss by increasing satiety (the feeling of fullness after eating).

While glucomannan shows promise as a weight loss aid, the review's authors note that more research is needed to determine the safety and efficacy of taking glucomannan for weight loss.

2) Cholesterol

Glucomannan may help keep cholesterol in check, suggests a 2008 report published in the American Journal of Clinical Nutrition. After analyzing 14 clinical trials on glucomannan, the report's authors concluded that glucomannan may lower total cholesterol and LDL ("bad") cholesterol. In addition, glucomannan appeared to reduce body weight and cut levels of triglycerides (harmful blood fats). However, the report's authors note that glucomannan does not seem to affect HDL ("good") cholesterol or blood pressure.

3) Constipation

Glucomannan may help treat childhood constipation, according to a 2004 study published in Pediatrics. The study involved 46 chronically constipated children, each of whom was treated with either glucomannan or a placebo for four weeks. Among the 31 children who completed the study, researchers found that glucomannan was more effective in alleviating constipation. Glucomannan also appeared to reduce abdominal pain.

See other constipation remedies.

4) Rheumatoid Arthritis

Glucomannan may help manage rheumatoid arthritis, according to preliminary research published in Neuro Endocrinology Letters. In tests on rats, the authors of a 2008 study found that certain antioxidants and anti-inflammatory compounds available in glucomannan may be beneficial in the treatment of rheumatoid arthritis.

5) Diabetes

Although there have been relatively few studies on the effects of glucomannan for diabetes, several small studies suggest that it may help.


Little is known about the safety of using glucomannan regularly or in the long term. However, there's some evidence that glucomannan may produce certain side effects (such as flatulence, abdominal pain, and digestive problems). If you're considering the use of glucomannan, talk to your doctor before beginning treatment.

Where to Find It

Widely available for purchase online, glucomannan powder, capsules, and tablets are sold in many natural-food stores and in stores specializing in dietary supplements.

Glucomannan is also found in shirataki noodles, a type of diet noodle with almost no calories or carbohydrates.

Using Glucomannan for Health

Due to a lack of supporting research, it's too soon to recommend glucomannan for any health condition. Supplements haven't been tested for safety and due to the fact that dietary supplements are largely unregulated, the content of some products may differ from what is specified on the product label. Also keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established. If you're considering the use of glucomannan, talk with your primary care provider first. Self-treating a condition and avoiding or delaying standard care may have serious consequences.

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