Supplement
Psyllium is a soluble fiber from Plantago ovata seed husks that forms a gel in the gut, helping regulate bowel movements. People mostly look at it for digestive health, and trials found it changed stool weight, while constipation symptoms eased in a larger review. The stool studies were small, though, and the constipation evidence is limited.
Sources: PMID 2831263; PMID 465439; PMID 35816465
- Updated
- How we grade
- 27 studies cited
- Best evidence
- Grade A
- Conditions studied
- 14
- Outcomes
- 68
- Graded outcomes
- 2443
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Fecal Weight Large Increase | Improves (the measure goes down) | Large effect | 3 studies | 47 people | ||
Studies that measured fecal weight | ||||||
| Intestinal Motility | Improves (the measure goes up) | 12 people | ||||
| Lipid Absorption | Improves (the measure goes up) | 4 people | ||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Fecal Weight Large Increase | Improves (the measure goes down) | Large effect | 3 studies | 32 people | ||
Studies that measured fecal weight | ||||||
| Flatulence | Changes; see studies | 1 study | 10 people | |||
Studies that measured flatulence | ||||||
| Intestinal Motility | Improves (the measure goes up) | 12 people | ||||
| Lipid Absorption | Improves (the measure goes up) | 4 people | ||||
Weight Loss & Maintenance
- Appetite: improves
- Weight: improves
- Body Mass Index (BMI): improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Appetite Small Decrease | Improves (the measure goes down) | Small effect | 3 studies | 47 people | ||
Studies that measured appetite | ||||||
| Weight | Improves (the measure goes down) | 3 studies | 465 people | |||
Studies that measured weight
| ||||||
| Body Mass Index (BMI) | Improves (the measure goes down) | 354 people | ||||
| Food Intake | Changes; see studies | 16 people | ||||
| Gastric Emptying Rate | Changes; see studies | 14 people | ||||
| Waist circumference | Improves (the measure goes down) | 354 people | ||||
High Cholesterol
- Blood glucose: improves
- Carbohydrate Absorption: improves
- Low-density lipoprotein (LDL): improves
Type 2 Diabetes
- Blood glucose: improves
- Low-density lipoprotein (LDL): improves
- Total cholesterol: improves
Metabolic Health
- Blood glucose: improves
- HbA1c: improves
- Insulin: changes; see studies
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Blood glucose Small Improvement | Improves (the measure goes down) | Small effect | 1 study | 962 people | ||
| HbA1c | Improves (the measure goes down) | 1 study | 523 people | |||
| Insulin | Changes; see studies | 575 people | ||||
| Insulin Resistance | Improves (the measure goes down) | 591 people | ||||
Constipation
- Constipation Signs and Symptoms: improves
- Fecal Weight: improves
- Stool Consistency: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Constipation Signs and Symptoms Moderate Improvement | Improves (the measure goes down) | Moderate effect | 1 study | 297 people | ||
Studies that measured constipation signs and symptoms | ||||||
| Fecal Weight | Improves (the measure goes down) | 3 studies | 15 people | |||
Studies that measured fecal weight | ||||||
| Stool Consistency | Improves (the measure goes up) | 297 people | ||||
High Blood Pressure
- Blood Flow: improves
- Blood Pressure: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Blood Flow Small Increase | Improves (the measure goes up) | Small effect | 1 study | 57 people | ||
| Blood Pressure | Improves (the measure goes down) | 1 study | 57 people | |||
Studies that measured blood pressure | ||||||
Dyslipidemia
- Blood glucose: improves
- Low-density lipoprotein (LDL): improves
- Total cholesterol: improves
Obesity
- Thermic effect of food (TEF)
- Weight: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Thermic effect of food (TEF) No effect | NoneNo effect | 1 study | 10 people | |||
Studies that measured thermic effect of food (tef) | ||||||
| Weight | Improves (the measure goes down) | 3 studies | 231 people | |||
Studies that measured weight
| ||||||
Overweight
- Blood Pressure
- Low-density lipoprotein (LDL): improves
- Weight: improves
General Cardiovascular Health
- Blood Pressure
- Low-density lipoprotein (LDL): improves
- Weight: improves
Ulcerative Colitis
- Ulcerative Colitis Symptoms: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Ulcerative Colitis Symptoms | Improves (the measure goes down) | 1 study | 102 people |
Diarrhea
- Diarrhea Symptoms: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Diarrhea Symptoms | Improves (the measure goes down) | 1 study | 211 people |
What the published studies found
2 automated readings
LDL cholesterol
The best available review (2018, 28 studies, 1,924 people) found an improvement in LDL cholesterol. That review studied individuals with or without hypercholesterolemia. All 10 studies read agree. The evidence is moderate.
10 studies counted of 10 read: 6 reviews and 4 trials (303 people in the trials).
- Meta-analysis, 2018; 28 studies, 1,924 people; individuals with or without hypercholesterolemia: improves (the review the verdict rests on).
significantly reduced LDL cholesterol (MD = -0.33
Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials - Meta-analysis, 2025; 41 studies, 2,049 people: improves. Psyllium supplementation and lipid profiles: systematic review and dose-response meta-analysis of randomized controlled trials
- Meta-analysis, 2020; 8 studies, 395 people: improves.
significant reduction in triglycerides, low-density lipoprotein
The effect of psyllium consumption on weight, body mass index, lipid profile, and glucose metabolism in diabetic patients: A systematic review and dose-response meta-analysis of randomized controlled trials - Meta-analysis, 2009; 21 studies, 1,030 people: improves.
Compared with placebo, consumption of psyllium lowered serum total cholesterol by 0.375 mmol/l (95% CI: …
Time- and dose-dependent effect of psyllium on serum lipids in mild-to-moderate hypercholesterolemia: a meta-analysis of controlled clinical trials - Meta-analysis, 2000; 8 studies, 656 people; men and women with hypercholesterolemia: improves.
LDL cholesterol by 7% (P < 0.0001)
Cholesterol-lowering effects of psyllium intake adjunctive to diet therapy in men and women with hypercholesterolemia: meta-analysis of 8 controlled trials - Meta-analysis, 1997; 12 studies, 404 people; hypercholesterolemic adults: improves.
The meta-analysis showed that subjects who consumed a psyllium cereal had lower TC and LDL-C …
Psyllium-enriched cereals lower blood total cholesterol and LDL cholesterol, but not HDL cholesterol, in hypercholesterolemic adults: results of a meta-analysis - Randomised trial, 2015; 51 people; brazilian dyslipidaemic children and adolescents: improves.
LDL-C (10·7%; - 0·36 mmol/l; P= 0·01)
Effects of psyllium on LDL-cholesterol concentrations in Brazilian children and adolescents: a randomised, placebo-controlled, parallel clinical trial - Randomised trial, 1993; 118 people; hypercholesterolemic men and women on high- or low-fat diets: improves.
LDL cholesterol levels decreased 5.8% and 7.2%
Efficacy of psyllium in reducing serum cholesterol levels in hypercholesterolemic patients on high- or low-fat diets - Randomised trial, 1990; 59 people: improves. Synergistic effects of psyllium in the dietary treatment of hypercholesterolemia
- Randomised trial, 1989; 75 people; patients with mild to moderate hypercholesterolemia: improves.
8.2% reduction in low-density lipoprotein cholesterol level
Cholesterol-lowering effects of psyllium hydrophilic mucilloid. Adjunct therapy to a prudent diet for patients with mild to moderate hypercholesterolemia
- Meta-analysis, 2018; 28 studies, 1,924 people; individuals with or without hypercholesterolemia: improves (the review the verdict rests on).
Body weight
The best available review (2023, 111 studies, 6,171 people) found an improvement in body weight. That review studied adults with overweight or obesity. 4 of the 9 studies read agree; 4 found no clear difference, 1 found a worse result. The evidence is moderate.
Possible harm: 1 study read reported a worse result for body weight with Psyllium. One abstract says: "The findings indicate that psyllium significantly increased body weight, with a WMD of 3.57 (95% confidence intervals: 1.43, 5.72; p-value < 0.05)." Check the studies below, and ask a doctor or pharmacist if this applies to you.
9 studies counted of 9 read: 5 reviews and 4 trials (191 people in the trials).
- Systematic review, 2023; 111 studies, 6,171 people; adults with overweight or obesity: improves (the review the verdict rests on). Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials
- Meta-analysis, 2025; 27 studies: worsens.
psyllium significantly increased body weight, with a WMD of 3.57
The effect of psyllium consumption on anthropometric indices: a systematic review and dose-response meta-analysis of randomized controlled trials - Meta-analysis, 2023; 6 studies, 354 people: improves.
effective for decreasing body weight (MD = -2.1 kg
Psyllium is a natural nonfermented gel-forming fiber that is effective for weight loss: A comprehensive review and meta-analysis - Meta-analysis, 2020; 8 studies, 395 people: no clear difference.
no significant change in high-density lipoprotein, body mass index, cholesterol, and weight
The effect of psyllium consumption on weight, body mass index, lipid profile, and glucose metabolism in diabetic patients: A systematic review and dose-response meta-analysis of randomized controlled trials - Meta-analysis, 2020; 22 studies: no clear difference.
did not find any significant effect of psyllium supplementation on body weight
The effects of psyllium supplementation on body weight, body mass index and waist circumference in adults: A systematic review and dose-response meta-analysis of randomized controlled trials - Randomised trial, 2019; 77 people; constipated patients with type 2 diabetes: improves.
weight (P < 0.001), BMI (P < 0.001), FPG (P = 0.004), cholesterol (P = …
Effect of flaxseed or psyllium vs. placebo on management of constipation, weight, glycemia, and lipids: A randomized trial in constipated patients with type 2 diabetes - Randomised trial, 2018; 51 people; patients with type 2 diabetes and chronic constipation: improves.
absolute change of body weight (-2.0 (-3.0, -1.0) kg
Effects of psyllium vs. placebo on constipation, weight, glycemia, and lipids: A randomized trial in patients with type 2 diabetes and chronic constipation - Randomised trial, 2018; 37 people; patients with type 2 diabetes: no clear difference.
Body weight change did not differ between the two groups.
Short-Term Supplementation of a Moderate Carbohydrate Diet with Psyllium Reduces Fasting Plasma Insulin and Tumor Necrosis Factor-α in Patients with Type 2 Diabetes Mellitus - Randomised trial, 1988; 26 people; 26 men with mild to moderate hypercholesterolemia: no clear difference. Cholesterol-lowering effects of psyllium hydrophilic mucilloid for hypercholesterolemic men
Key findings
- Fecal WeightImproves (the measure goes down)
- AppetiteImproves (the measure goes down)
- Blood glucoseImproves (the measure goes down)
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- Grade A
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Studies cited
27 studies from PubMed
- Comparison of the effects of psyllium and wheat bran on gastrointestinal transit time and stool characteristics
- The effects of a supplement of dietary fibre on faecal excretion by human subjects
- An unfermented gel component of psyllium seed husk promotes laxation as a lubricant in humans
- Inhibitory actions of a high fibre diet on intestinal gas transit in healthy volunteers
- The effect of a Plantago ovata seed containing preparation on appetite variables, nutrient and energy intake
- Effects of amount and type of dietary fibre (soluble and insoluble) on short-term control of appetite
- Correlation between echographic gastric emptying and appetite: influence of psyllium
- Psyllium is a natural nonfermented gel-forming fiber that is effective for weight loss: A comprehensive review and meta-analysis.
- Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials.
- The acute effects of psyllium on postprandial lipaemia and thermogenesis in overweight and obese men
- Influence of sibutramine, orlistat and Ispaghula in reducing body weight and total body fat content in obese individuals
- Psyllium supplementation in adolescents improves fat distribution & lipid profile: a randomized, participant-blinded, placebo-controlled, crossover trial
- Cholesterol-lowering effects of soluble-fiber cereals as part of a prudent diet for patients with mild to moderate hypercholesterolemia
- The effect of psyllium consumption on blood pressure: Systematic review and dose-response meta-analysis of randomized controlled trials.
- Randomized, double-blind, placebo-controlled, two-period crossover clinical trial of psyllium fiber in children with hypercholesterolemia
- Therapeutic effects of psyllium in type 2 diabetic patients
- Lipid- and glucose-lowering efficacy of Plantago Psyllium in type II diabetes
- The effects of foods on LDL cholesterol levels: A systematic review of the accumulated evidence from systematic reviews and meta-analyses of randomized controlled trials
- Time- and dose-dependent effect of psyllium on serum lipids in mild-to-moderate hypercholesterolemia: a meta-analysis of controlled clinical trials.
- The effects of psyllium on lipoproteins in type II diabetic patients
- Galactomannans are the most effective soluble dietary fibers in type 2 diabetes: a systematic review and network meta-analysis.
- Effectiveness and Safety of Ayurvedic Medicines in Type 2 Diabetes Mellitus Management: A Systematic Review and Meta-Analysis.
- The effects of 12-week psyllium fibre supplementation or healthy diet on blood pressure and arterial stiffness in overweight and obese individuals
- The effect of fiber supplementation on chronic constipation in adults: an updated systematic review and meta-analysis of randomized controlled trials.
- Randomized clinical trial of Plantago ovata seeds (dietary fiber) as compared with mesalamine in maintaining remission in ulcerative colitis. Spanish Group for the Study of Crohn's Disease and Ulcerative Colitis (GETECCU)
- The effect of fiber supplementation on the prevention of diarrhea in hospitalized patients receiving enteral nutrition: A meta-analysis of randomized controlled trials with the GRADE assessment.
- The effect of psyllium on fasting blood sugar, HbA1c, HOMA IR, and insulin control: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials.