Glucomannan has been investigated for its effects on weight reduction, diabetes, constipation, cholesterol, lung cancer, and atopic diseases, as well as its use as a prebiotic. However, there is a lack of adequately sized quality clinical trials to support these uses.
Glucomannan is a type of vegetable fiber that comes from the root of a plant known as konjac (Amorphophallus konjac, to be specific). This fiber is commonly used in Asian health foods, and many herbal supplements now contain glucomannan. In addition to its use in foods, the fiber is often used for the following purposes:
To relieve constipation
To lower cholesterol
To aid in weight loss
To lower blood sugar (in people with type 2 diabetes).
Glucomannan works like any other fiber product to relieve constipation and lower cholesterol, as well as to help with obesity and type 2 diabetes. It is a fiber that is not absorbed into the body (it stays in the digestive tract). It increases the water absorption into the stool in the colon, helping to relieve constipation. It probably works to lower cholesterol by helping the body get rid of cholesterol through the stool. Because fiber slows the emptying of the stomach, it can help people feel full and can help keep blood sugar more even. This is probably how glucomannan fiber helps with obesity and type 2 diabetes.
Glucomannan is a type of fiber that is used both in food preparation and in herbal supplements. It comes from the root of a plant known as konjac (Amorphophallus konjac). In addition to its use in food preparation, glucomannan is often used for the following purposes:
To lower blood sugar (in people with type 2 diabetes)
To relieve constipation
To lower cholesterol
To aid in weight loss.
There is also some evidence that glucomannan can help prevent food poisoning from food contaminants and toxins (although studies have focused on animals for this use). Recent research has also suggested that glucomannan can help treat eczema-like skin reactions in mice.
Like other types of fiber, glucomannan can be consumed as part of your diet, although many people find it difficult to obtain enough fiber just through diet. Glucomannan foods are popular in Asian health food markets, but they may be difficult to find in some areas. For people who have trouble eating enough fiber, fiber supplements (including glucomannan supplements) may be useful.
Because of glucomannan's potential ability to lower blood glucose, use caution in patients receiving oral hypoglycemic agents, insulin, or alternative medicines that could potentially lower glucose levels. Additionally, glucomannan may reduce the bioavailability of other oral medications. Thus, it is recommended that other medications be taken 1 hour before or 4 hours after glucomannan administration.
Severe esophageal and GI obstruction have been reported with glucomannan tablets. The hypoglycemic effects are potentially dangerous to patients with diabetes. Glucomannan has been linked in case reports to cholestatic hepatitis and occupational asthma. Minor adverse effects are normally GI related and include diarrhea, flatulence, and bloating.
Glucomannan (as well as any other fiber supplement) is most likely to cause side effects of the digestive tract. These common glucomannan side effects may include:
Gas
Bloating
A feeling of fullness
Nausea
Abdominal pain (stomach pain)
Diarrhea.
As with all fiber supplements, these side effects can probably be avoided by gradually increasing your fiber intake, giving your body a chance to adjust to the fiber.
There are a number of side effects with glucomannan that you should report to your healthcare provider. These include, but are not limited to:
Difficulty swallowing or a feeling that glucomannan is stuck in your throat
Very severe diarrhea (or diarrhea that does not go away)
Changes in your blood sugar (which is important for people with diabetes)
Breathing problems (from accidentally inhaling glucomannan powder)
Signs of an allergic reaction, such as a rash, hives, itching, swelling of the mouth or throat, wheezing, or difficulty breathing.
it does what it promise November 02, 2007, From New York
I used it for colesterol,it worked and beside I loose weight too
Great for appetite control June 22, 2010, From Ohio
Taken as instructed, it really helps create a feeling of fullness. I haven't found it to be very helpful as fiber, but as a weight loss aid, it seems to work pretty well, and at a good price. I've already ordered another bottle.
Awful stuff June 01, 2010, From Arizona
This stuff made me feel all bloated and gave me the absolutely stinkiest gas I have ever had in my life. It also plugged me up instead of having the opposite effect. Prior to taking this I maintained regular BM with acidophilus and kefir taken nightly. While taking glucomannan I was fairly constipated and I drink a lot of water. It had no effect on my weight at all.
improves blood sugar stabilization December 08, 2010, From Texas
Decreased my appetite for first couple of meals when I took 45 minutes prior to eating. Appetite suppression not so good on following days but I have noticed that my craving and lack of will power in the grocery store has greatly diminished. It has been very hard for me to leave the store without some goody from the bakery department which I often eat in the car on my way home (red flag on this habit.) I'm obese... Since taking this, I seem to not have this tremendous attraction for buying something sugary and unhealthy. I actually left the store yesterday without even considering it. That alone makes this product worth a lot to me. I didn't get diarhea like some report or constipation like others (from forums on the web). My bowels seem to be doing okay - guess I'm drinking enough water when I'm taking this - very important it says. Anyway, I'm hooked on this. I take a lot of vitamins but this one is moving up to near the top of the list of ones I don't want to do without.
Made me constipated! August 29, 2010, By Mimi From France
Tried this and stopped after 4 days. It made me constipated. Did not go to the bathroom for 5 days! ...
... Glucomannan... February 10, 2011, From California
Since I have been using this product my cravings ( which had been very strong ) for sugar have banished and I am satisfied with less food .I take three capsules in the morning and then again in the afternoon with ... water.
Easy on the stomach January 08, 2010, From Washington
This is the product for me! It doesn't bother my stomach at all. Great stuff!
Great Great Great! June 16, 2011, From Connecticut
Great product! Works on the cravings and most of all if you don't get enough fiber it works great for that also.
Great hunger supresant June 28, 2011, From California
This product is great. It takes away any hunger cravings... Highly recommended!