Psyllium husk has a long history of use in traditional and herbal medicines. Psyllium husk is derived from the seed of the plantago ovata plant. Besides plantago ovata, psyllium is also known as ispaghula and isapgol. Plantago ovata is an annual herb native to Asia, the Mediterranean region, and North Africa. Psyllium grows in sandy and silty soils. India provides about 85 percent of the psyllium available in the world market.
Psyllium is mainly used as a dietary fiber, which is not absorbed by the small intestine. The purely mechanical action of psyllium mucilage absorbs excess water while stimulating normal bowel elimination. Although its main use has been as a laxative, it is more appropriately termed a true dietary fiber and as such can help reduce the symptoms of both constipation and mild diarrhea. The laxative properties of psyllium are attributed to the fiber absorbing water and subsequently softening the stool.
The United States is the world's largest importer of psyllium husk, with over 60% of total imports going to pharmaceutical firms. In Australia, psyllium husk is used to make Bonvit psyllium products. In the UK, ispaghula husk is used in the popular constipation remedy Fybogel.
Psyllium mucilage is also used as a natural dietary fiber for animals. The dehusked seed that remains after the seed coat is milled off is rich in starch and fatty acids and is used in animal feed.