Uses of this Supplement
Irritable Bowel Syndrome
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Cholestyramine Resin
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Look Up > Supplements > Psyllium
Dietary Sources
Commercial Preparations
Therapeutic Uses
Dosage Ranges and Duration of Administration
Side Effects/Toxicology


Psyllium, also called psyllium seed, is a soluble fiber that comes from a perennial weed, a relative of the common plantain herb of the family Plantaginaceae, of which there are about 250 species worldwide. (It is not the same as the edible plantain Musa paradisiaca.) Psyllium seeds are coated in mucilage, 1.5 to 3.5 mm, oval or boat-shaped, and dark ruddy brown in color, and produce no odor and almost no taste.

Psyllium seeds or husks can be purchased in bulk from health stores or pharmacies. Psyllium can also be found as an ingredient in commercially prepared laxative products such as Metamucil (which contains psyllium hydrophilic muciloid), which undergo more processing than all-natural products.

Used as a dietary fiber, psyllium is a bowel tonic and gentle bulk laxative that attracts water and creates larger, softer stools. Doctors and herbalists recommend psyllium as a stool softener and bulking agent to relieve constipation, diarrhea, hemorrhoids, irritable bowel syndrome, and Crohn's disease. Considered a good intestinal cleanser and stool softener, psyllium is one of the most popular fibers available. Unlike bran fiber, psyllium does not cause excessive gas and bloating.

Soluble fibers such as psyllium can help prevent the intestine from absorbing cholesterol, and several studies have found that adding psyllium to the diet can produce a significant reduction in serum cholesterol in the absence of other dietary modifications and can increase cholesterol reduction when coupled with cholesterol-lowering medication.

High-fiber foods, including psyllium, aid in reducing the risk of hypertension, heart disease, and even some cancers. Studies examining the effects of psyllium husks on colon cancer have found that the fiber strongly reduces the ability of a carcinogen to cause colon cancer. Animal studies found that rats fed psyllium husks produced the highest fecal bacteria counts and the bulkiest and most moist stools. Animal studies also showed that the greater the fiber intake, the lower the rate of fatal colon disease. Other studies have shown that high-fiber diets appear to be protective against breast and other cancers as well.

Several studies have shown that adding fiber to the diet can significantly increase weight loss even in the absence of calorie restriction. Clinical studies have shown that fiber supplements enhance blood sugar control and reduce calorie absorption by as much as 30 to 180 calories a day, which would result in a 3- to 18-pound weight loss over the course of a year. Both soluble and insoluble fibers aid weight loss. Water-soluble fibers such as psyllium, taken with water before meals, create a feeling of fullness by expanding to a gelatinous mass in the stomach, causing the dieter to consume smaller quantities of food. Fiber supplements also aid blood sugar and insulin control. Because fiber supplements absorb water rapidly, people who use fiber as a weight-reducing aid must take care to be well hydrated by drinking at least six to eight full glasses of water each day.

Dietary Sources

Psyllium seed or husk (from plantain herb)


Psyllium is available as psyllium seed or husk, or as a combination of the two. Its constituents include acids, alkaloids, amino acids, fixed oil, protein, iridoids, tannins, flavonoids, and a variety of sugar and polysaccharide components and other plant carbohydrates in the seed mucilage.

Commercial Preparations

Psyllium is an ingredient in some commercially prepared laxatives, including Metamucil.

It is also found in some combination herbal remedy products, such as Aerobic Bulk Cleanse (ABC), which contains blond psyllium seed husks and licorice and hibiscus herbs. ABC is used to heal and cleanse the colon and to treat diarrhea and constipation.

Therapeutic Uses
  • Relieves constipation as a stool softener and gentle, bulk laxative
  • Relieves diarrhea
  • Cleanses and helps heal the colon
  • Acts as a fiber supplement
  • Lowers cholesterol
  • Treats irritable bowel syndrome
  • Treats hemorrhoids
  • Aids weight reduction
  • Acts as a cancer inhibitor

Dosage Ranges and Duration of Administration

There is no RDA for psyllium, but herbal and health professionals recommend using to 2 tsp. of psyllium one or two times a day.

Add to 2 tsp. of psyllium seed to 1 cup (8 oz.) of warm water, mix well, then drink immediately (before it becomes too thick to consume; psyllium thickens rapidly when exposed to water). It may be beneficial to begin with a low dose, such as 1 tsp. in an 8-oz. glass of water, then increase to 2 tsp. if needed.

For irritable bowel syndrome, take psyllium fiber daily, starting with 1 tsp. in water once a day, then gradually increase psyllium intake: every three or four days, increase the amount by 1 tsp. in another glass of water up to a maximum of four glasses every day.

Psyllium may be taken first thing in the morning or at bedtime.

Side Effects/Toxicology

If taken at the same time or within one hour of taking medications, psyllium can interfere with their absorption and effectiveness.

It is possible to develop sensitivity to psyllium in breakfast cereal, according to a 1990 Journal of the American Medical Association report, which described a nurse who had in the past dispensed laxatives that contained psyllium and later suffered anaphylaxis upon exposure to a breakfast cereal that contained psyllium.


Use in children only under the direction of a qualified health care provider.

Psyllium must always be taken with at least a full 8 oz. (1 cup) of water.

Do not take guar, another soluble fiber supplement whose mechanism is similar, at the same time as psyllium; use one or the other, but not both.

Diabetics should use caution when taking herbs such as psyllium (also marshmallow root and flax) that have a high mucilage content because they may affect blood sugar.


In a study with 4 healthy male volunteers, administration of carbamazepine (200 mg po) with ispaghula husk (3.5 g) reduced the bioavailability of the drug by 1.22 mg/mL and delayed achievement of maximum plasma concentrations (Etman 1995). The decrease in carbamazepine absorption due to fiber consumption could lead to subclinical concentrations of the drug. However, there were no adverse effects reported with the use of psyllium hydrophilic mucilloid (3.4 g bid) in a patient taking carbamazepine (1000 mg/day) (Ettinger et al. 1992). If psyllium is used to ease constipation associated with carbamazepine therapy, the patient should be monitored carefully to assure that plasma concentrations of the drug remain within therapeutic range.

Cholestyramine Resin; Colestipol

Preclinical and clinical data suggest that psyllium powder can be combined with bile acid sequestrants for the treatment hyperlipidemias. In a study of cholesterol-fed hamsters, various levels of cholestyramine resin were administered with or without psyllium powder (Turley et al. 1996). Although high-dose cholestyramine (3% of diet) was most effective in lowering blood and liver cholesterol, the combination of cholestyramine and psyllium was almost as effective, especially at higher psyllium doses (4% of diet). The combination therapy was more effective in promoting fecal bile acid excretion and inhibiting intestinal cholesterol absorption than the resin alone.

Clinically, a randomized, double-blind controlled trial of 121 patients with moderate hypercholesterolemia examined the effects of colestipol (5 g tid), psyllium (5 g tid), and a combination of colestipol (2.5 g tid) and psyllium (2.5 g tid) for 10 weeks (Spence et al. 1995). Combination therapy was tolerated better than colestipol monotherapy and was as effective as either agent alone.


A study with six healthy male volunteers ages 28 to 40 investigated the effects of psyllium on lithium sulfate treatment (12 mEq in 100 mL of water/day) (Toutoungi et al. 1990). Concomitant administration of lithium and psyllium reduced lithium absorption approximately 14%. A single case report of an interaction between psyllium and lithium supports these findings (Perlman 1990). In spite of increasing oral doses, blood lithium levels remained within sub-therapeutic range until psyllium (1 tsp bid) was discontinued. Withdrawal of psyllium caused a prompt increase in blood lithium levels. To minimize the effects on absorption, psyllium should be taken at least one hour after taking lithium. Lithium levels should be monitored frequently whenever psyllium is introduced or withdrawn.


Alabaster O, Tang ZC, Frost A, Sivapurkar N. Potential synergism between wheat brain and psyllium: enhanced inhibition of colon cancer. Cancer Lett. 1993;75:53-58.

Ashraf W, Park F, Lof J, Quigley EM. Effects of psyllium therapy on stool characteristics, colon transit and anorectal function in chronic idiopathic constipation. Aliment Pharmacol Ther. 1995;9:639-647.

Balch J, Balch P. Prescription for Nutritional Healing. 2nd ed. Garden City Park, NY: Avery Publishing Group; 1997.

Etman MA. Effect of a bulk forming laxative on the bioavailability of carbamazepine in man. Drug Dev Ind Pharm. 1995;21(16):1901-1906.

Ettinger AB, Shinnar S, Sinnett MJ, Moshe SL. Carbamazepine-induced constipation. J Epilepsy. 1992;5(3):191-193.

Fernandez-Banares F, Hinojosa J, Sanchez-Lombrana JL, et al. Randomized clinical trials of Platago ovata seeds (dietary fiber) as compared with mesalaminein maintaining remission in ulcerative colitis. Am J Gastroenterol. 1999;94:427-433.

Giller R, Matthews K. Natural Prescriptions. New York, NY: Carol Southern Books; 1994.

Kirschmann G, Kirschman J. Nutrition Almanac. 4th ed. New York, NY: McGraw-Hill; 1996.

McRorie JW, Daggy BP, Morel JG, Diersing PS, Miner PB, Robinson M. Psyllium is superior to docusate sodium for treatment of chronic constipation. Aliment Pharmacol Ther. 1998;12:491-497.

Moss R. Cancer Therapy. Brooklyn, NY: Equinox Press, Inc.; 1992.

Murray M. Encyclopedia of Nutritional Supplements. Rocklin, Calif: Prima Publishing; 1996.

Perlman BB. Interaction between lithium salts and ispaghula husk [letter]. Lancet. 1990;355:416.

Rodrigues-Moran M, Guerrero-Romero F, Lazcano-Burciaga G. Lipid- and glucose-lowering efficacy of Plantago Psyllium in type II diabetes. J Diabetes Complications. 1998;12:273-278.

Spence JD, Huff MW, Heidenheim P et al. Combination therapy with colestipol and psyllium mucilloid in patients with hyperlipidemia. Ann Intern Med. 1995;123:493-499.

The Review of Natural Products. St. Louis, Mo: Facts and Comparisons; 1998.

Toutoungi M, Schulz P, Widmer J, et al. Probable interaction of psyllium and lithium. Therapie. 1990;45(4):358-360.

Turley SD, Daggy BP, Dietschy JM. Effect of feeding psyllium and cholestyramine in combination on low density lipoprotein metabolism and fecal bile acid excretion in hamsters with dietary-induced hypercholesterolemia. J Cardiovasc Pharmacol. 1996;27:71-79.

Copyright © 2000 Integrative Medicine Communications

This publication contains information relating to general principles of medical care that should not in any event be construed as specific instructions for individual patients. The publisher does not accept any responsibility for the accuracy of the information or the consequences arising from the application, use, or misuse of any of the information contained herein, including any injury and/or damage to any person or property as a matter of product liability, negligence, or otherwise. No warranty, expressed or implied, is made in regard to the contents of this material. No claims or endorsements are made for any drugs or compounds currently marketed or in investigative use. The reader is advised to check product information (including package inserts) for changes and new information regarding dosage, precautions, warnings, interactions, and contraindications before administering any drug, herb, or supplement discussed herein.