Psyllium husk
Gut
Soluble fibre studied for regularity, cholesterol and satiety.
What the evidence says
Large, consistent human evidence for constipation, stool form and LDL reduction. One of the best-supported gut interventions available.
What studies used
5–10 g daily with plenty of water. Any time, always with water.
Reported from published studies and product labelling — a record of what was used in research, not a recommendation. What is right for you is a conversation with a clinician.
Watch out for
- Without enough water it makes things worse
- Start low — sudden fibre jumps cause bloating
Evidence base
substantial literature
Strong human evidence: either a phase 3 or 4 trial report alongside review-level evidence, or ten or more randomised controlled trial reports.
This letter measures how much human research exists, not whether it works for you — the tier above (Strong) is the read on quality.
Research (12)
- The Effect of Psyllium Husk on Intestinal Microbiota in Constipated Patients and Healthy ControlsInt J Mol Sci · 2019
- Psyllium: a useful functional ingredient in food systemsCrit Rev Food Sci Nutr · 2022
- Effects of dietary fibers or probiotics on functional constipation symptoms and roles of gut microbiota: a double-blinded randomized placebo trialGut Microbes · 2023
- Psyllium2006
- Psyllium Husk: A Comprehensive Review of its Functional Properties, Health Benefits, Mechanisms of Action, and Potential Adverse EffectsCurr Nutr Rep · 2026
- Nutrition, Physical Activity and Supplementation in Irritable Bowel SyndromeNutrients · 2023
- The role and therapeutic effectiveness of Plantago ovata husk (psyllium husk) in the prevention and non-pharmacological treatment of gastrointestinal diseases. Part 2. Clinical use of psyllium husk in the treatment of constipation and diarrheaPrz Gastroenterol · 2025
- The role and therapeutic effectiveness of Plantago ovata seed husk (psyllium husk) in the prevention and non-pharmacological treatment of gastrointestinal diseases. Part 1. Clinical use of psyllium husk in the treatment of irritable bowel syndrome, ulcerative colitis, and colorectal cancerPrz Gastroenterol · 2024
- Synergistic effects of Ligilactobacillus salivarius Li01 and psyllium husk prevent mice from developing loperamide-induced constipationFood Funct · 2024
- Application of Psyllium Husk as a Friendly Filtrate Reducer for High-Temperature Water-Based Drilling FluidsACS Omega · 2022
- Psyllium husk powder increases defecation frequency and faecal score, bulk and moisture in healthy catsJ Feline Med Surg · 2024
- Psyllium husk (Metamucil®) induced perennial asthma: A case reportRespir Med Case Rep · 2024
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