Cambridge University Botanic Garden -- Cambridge, England, Plant Delights Nursery, Inc.

Amorphophallus konjac is a large, perennial exotic Asian plant. It grows a single, elongated center called a corm and a single large leaf that wraps around it. The corm is the part of the plant that is used, as well as its tuber, which is commonly called the konnyaku potato. Glucomannan is its scientific name, and its other common names include konjac mannan, devil's tongue, konjac, elephant-foot yam, snake plant and konnyaku.


Amorphophallus konjac forms a gelatinous mass when mixed with water. When ingested, the body does not digest Amorphophallus konjac. Rather, the gelatinous mass moves through the digestive system, stimulating the peristalsis of the stomach and the intestines. The mass also grabs substances along the digestive tract as it moves through the digestive system. This property is why Amorphophallus konjac is often used as a natural laxative.



Amorphophallus konjac acts as a diet aid that has many benefits. Its ability to swell when mixed with water allows it to fill the stomach. It also moves through the digestive system very slowly, making the appetite feel satisfied for a longer period of time. This characteristic of Amorphophallus konjac is beneficial in treating obesity. As a part of a weight loss plan, coupled with exercise and drinking plenty of water, it may aid in the treatment of obesity.


Amorphophallus konjac has an effect on diabetes as well. Its ability to move through the digestive tract very slowly also slows down carbohydrate absorption. This slowed absorption will keep the blood sugar at a moderate level. Amorphophallus konjac also acts to trap food and waste residues as it moves through the digestive system. This internal scrubbing opens the pores along the digestive tract, which in turn increases absorption. It also regulates absorption. Its presence can also block substances that are easily reabsorbed such as excess bile acids. The digestive regulatory quality of Amorphophallus konjac makes it a natural, alternative agent in the treatment and regulation of diabetes and high cholesterol.


Amorphophallus konjac is commonly used in Asian cuisine. Its tubers can be prepared like potato dishes, and they are also made into cereals and Asian noodles. It can also be made into a flour and used as a food thickener. Its natural sugar can be extracted and makes an ideal natural sugar substitute. Candies are even made from it.

Amorphophallus konjac is also used as a food preservative and as a thickening and carrying agent in pharmaceutical products. In cosmetics it is used to give body to a variety of beauty products. It is also used in wound treatment as a protective layer that does not irritate the skin.


Amorphophallus konjac is a healthy food substance, even though it is indigestible. It is an alkaline food that provides several nutrients to the body. It contains water, protein, carbohydrate, lipids, sodium, potassium, magnesium, iron, phosphorus, copper, zinc, vitamin A, vitamin E, vitamin D, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, pantothenate, niacin, fatty acid, folic acid and dietary fiber.


Amorphophallus konjac must be consumed with at least 8 ounces of water to prevent esophageal blockage.

Amorphophallus konjac is not digestible, rather it is just a fibrous substance that passes through the digestive tract. Caution has to be taken when used for children. It is also recommended for a woman not to take Amorphophallus konjac if she is breastfeeding or pregnant.

People with diabetes should avoid taking Amorphophallus konjac frequently. There is the possibility of lowering the blood sugar to dangerous levels from prolonged use. Although Amorphophallus konjac is a natural substance, it has to be administered under the supervision of a health care professional.

Amorphophallus konjac forms a thick and slimy gel when mixed with fluids and consumed. This may block essential drug and nutrient absorption, therefore wait two hours before and after consuming Amorphophallus konjac to take medications.

It is not recommended to take Amorphophallus konjac with the following herbs because they all act as natural agents that can also lower the blood sugar. Avoid combining it with herbs such as kudzu, ginger, eleuthero, panax ginseng, and fenugreek.