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Psyllium Husk: The Complete Guide

Evidence Based

Given its huge popularity, psyllium husk may just be the Prom King & Queen of  fibers!  From helping people with constipation to lowering cholesterol, it seems to be an amazing fiber for gut and overall health.  But before we get all love-eyed, let’s look over the research to see which benefits are real and which are not.  Let’s go!

In a hurry? Jump to
What is it? Benefits Side Effects Summary & Verdict
Researched & Written by
Bailey Franzen MS, RDN
Bailey Franzen MS, RDN
Registered Dietitian Nutritionist
Carolyn Quijano MS, RDN
Carolyn Quijano MS, RDN
Registered Dietitian Nutritionist

Edited by Digest Life team

Last Updated: 7 April 2021

What is psyllium husk powder?

Psyllium is derived from the Plantago ovata plant’s seeds, which are cultivated in India, Pakistan, and Iran. So you may see it referred to as Plantago ovata, ispaghula, aspaghol, spogel, ghoda, jiru, obeko, bazarqutuna, and grappicol(S), but let’s stick with calling it psyllium.

Psyllium is the type of fiber found in your grandma’s Metamucil. While Metamucil may have made psyllium popular in America, psyllium has been used for ailments for centuries (S).

If you’ve read our high fiber diet article, you know that different fibers can be categorized based on solubility, viscosity, and fermentability. Psyllium is considered to be a soluble, viscous, and poorly-fermented fiber. This means that psyllium is dissolvable in water (soluble), water-holding, and gel-forming (viscous) and that psyllium has less of a prebiotic effect (poorly-fermenting)(S).

Because psyllium is a poorly fermented fiber, it’s also not a high gas-producing fiber. This makes psyllium a good fiber choice for people sensitive to excess gas production (e.g., people with irritable bowel syndrome)(S).

What are the benefits of psyllium husk?

From our extensive research we have identified 6 benefits psyllium may offer:

  1. Constipation/bulk laxative
  2. Irritable Bowel Syndrom (IBS)
  3. Inflammatory Bowel Disease (IBD)
  4. Lower cholesterol
  5. Diabetes/lower blood glucose response
  6. Changes to the microbiome

1.  Constipation

Psyllium is approved by the FDA as a laxative.

The primary mechanism for softening stool and acting as a laxative is its’ gel-forming and water-holding capacity. It relieves constipation by increasing the stool’s water content, which helps normalize stools and evacuation(S).

Stool water content matters. Soft, normal, and hard stools contain 77%, 74%, and 72% water, respectively. Adding psyllium can change the content in a seemingly small way, which results in a significant change(S).

Psyllium may be more effective than docusate sodium (a common laxative) in increasing stool water content and laxation in people with constipation.

Taking psyllium for constipation
Study Result Dosage
↑ stool frequency and consistency

↓ pain on defecation

5g twice per day (S)
↑ number of complete stools per week

↑Bristol stool score (stool went from being hard/pebbly to softer/better formed)

↓ colonic transit time and abdominal pain

3.5g three times per day (S)
↑Fecal weight and moisture with improvements in laxation 8.8-25 g per day source


2.  IBS

Psyllium is recommended by the American College of Gastroenterology for controlling overall symptoms in IBS.

Psyllium’s ability to hold water and bulk-forming laxative effect helped patients control IBS, constipation, and diarrhea. These mechanisms make stools easy to pass (S).

Psyllium delays gastric emptying, probably by increasing meal viscosity, and reduces the acceleration of colon transit, possibly by delaying the production of gaseous fermentation products (S).

Children with IBS experienced less pain when supplementing with psyllium (S).

Psyllium ferments slowly and is a ‘green’ light on the Low FODMAP diet (source Monash).

Taking psyllium for IBS
Study Result Dosage
↓ abdominal pain in patients with IBS 3.5 g two or three times per day
↓ pain in children with IBS 6 g daily (s)

3.  IBD

Psyllium may maintain remission rates of ulcerative colitis. Source

More research should be conducted with psyllium and IBD.

Taking psyllium for IBD
Study Results Dosage
↑remission rates in ulcerative colitis 10g twice daily for a year (total dose of 20g daily)

4.  Cholesterol

The FDA recognizes the health claim between psyllium and reduction of cardiovascular disease risk when taken as part of a low-cholesterol, low-saturated-fat diet.

Psyllium lowers both total and low-density lipoprotein (LDL) cholesterol (the bad kind).

Cholesterol is reduced due to its’ binding action in two ways. It binds to dietary cholesterol while increasing the viscosity of stools which carries cholesterol out of the body. It also binds to bile acids, which leads to lower cholesterol levels.

Taking psyllium for lowering cholesterol levels
Study Results Dosage
↓LDL and total cholesterol 10-15 g per day Source, source,  source, source

5.  Diabetes

Psyllium’s solubility allows more time for carbohydrates to be absorbed which lowers the glycemic response by slowing the release of sugar into the blood.

The weight of dietary fiber plays an essential role in regulating blood sugar levels. The higher the weight of soluble fiber, the higher the viscosity and the greater the ability to lower blood glucose response.

When psyllium husk was manufactured into cereals, it had a similar effect on glucose response as supplementing. So psyllium husk can be supplemented in the diet or incorporated into food sources to aid in blood sugar control.

Some studies show that supplementing psyllium may decrease appetite and induce weight loss, but more studies are needed (S).

Taking psyllium with diabetes
Study Results Dosage
↓Blood glucose in people with type 2 diabetes 14-15g per day source  source
↓Appetite 10.6-20 g per day (mild effect)  source source source
↓ fasting plasma glucose levels 3.5 g three times per day, 20 minutes before meals

6.  Changes to the microbiome

Psyllium supplementation has been shown to create small but significant changes to the gut microbiome. One study done in people with constipation showed an increase in certain gut bacteria after supplementing with psyllium (Lachnospira, Faecalibacterium, Phascolarctobacterium, Veillonella, and Sutterella) and a decrease in other types (Coriobacteria and Christenella). Interestingly, no major microbiome changes were seen in people who did not suffer from constipation that supplemented psyllium. There was an increase in butyrate-producing microbes likely due to increased water content in stool induced by psyllium supplementation.  source

Taking psyllium and the microbiome
Study Results Dosage
↓/↑in certain gut bacteria 21 g per day (7-14 g doses) Metamucil source

Other uses

Because of its’ viscous and binding properties, psyllium is being used as a food additive:

  • Substitute for gluten
  • Texture modifier
  • Natural dietary fiber soure\ce
  • Gelling agent
  • Thickeners and binder
  • Improves mouth feel and viscosity
  • Emulsion and foam stabilizations(S)

What are potential side effects of pysllium?

If not taken with sufficient fluids, psyllium may cause adverse effects such as worsened constipation, bowel obstructions, or choking. SS

Summary & Verdict

  • Psyllium is a soluble, viscous, poorly fermenting fiber that has been used as a natural health aid for centuries.
  • Psyllium helps to relieve constipation.
  • Psyllium may relieve abdominal pain, diarrhea, and/or constipation in those with IBS.
  • LDL and total cholesterol levels may be decreased with psyllium supplementation
  • More research is needed for psyllium and IBD, weight loss, and appetite suppression.
  • Psyllium supplementation has been shown to change the microbiome in people with constipation.
  • Psyllium should be taken with an adequate amount of water to prevent choking or bowel obstruction.
  • Common suggested instructions is to drink 8 oz of water with 1 tsp (5 g) of psyllium powder.