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Psyllium (ispaghula husk)
Psyllium (ispaghula husk) — what the European monograph actually supports, what it is not for, the form and how long it is meant to be used, side effects, and the 3 medicine interactions documented for it.
This is a reference page, not a diagnosis and not a prescription. Herbal products are real pharmacology: they have effects, side effects and interactions with medicines. Tell your doctor and your pharmacist everything you take, including teas and supplements, and never stop or change a prescribed medicine because of anything you read here.
What it is
Plantago ovata Forssk. — seed husk (Plantaginis ovatae testa)
Local names across the region this site serves: psüllium (ET) · psyllium (FI) · псиллиум (RU).
Grouped here under Digestion, bloating and the bowel. Regulatory position: EU herbal monograph — well-established use.
What the evidence supports
The registered indication: Constipation, and conditions in which easy defecation with a soft stool is desirable; also used to increase dietary fibre intake.
Psyllium barely behaves like a drug at all: the husk is soluble fibre that absorbs many times its weight in water and forms a gel, which softens hard stool and firms loose stool at the same time. That two-way action is why it is used in irritable bowel syndrome as well as in constipation, and why it is usually the first thing to try before a stimulant laxative. Reviews of randomised trials also show a modest, consistent reduction in LDL cholesterol, which is unusual company for a herbal product. The safety rule is simple and absolute: always take it with a full glass of liquid and keep drinking through the day. Taken dry, or with too little fluid, it can swell in the throat or gut and cause an obstruction — that is what the warning on every pack is about, and it is why it should not be taken immediately before lying down.
A — Recognised efficacy A European Union herbal monograph carries a well-established-use indication for a defined preparation, meaning the regulator accepted clinical evidence.
What it is not for
Sudden severe abdominal pain, suspected obstruction, or a new unexplained change in bowel habit. Fibre added on top of an obstructed bowel makes things worse, not better.
Form, strength and how long
Husk or powdered husk in sachets, granules and capsules. Whole-seed preparations behave differently from husk.
Duration. Suitable for continued use, unlike stimulant laxatives — but symptoms that persist beyond a couple of weeks still deserve a look.
No gram figure appears on this page on purpose. The plant part, the extraction solvent and the drug-to-extract ratio together define a preparation, and a number taken from one does not describe another. The reasoning is set out on the hub; the amount that applies to you is the one printed on the pack you are holding, and a pharmacist will read it with you.
Side effects
Bloating and wind in the first days, easing as the gut adapts. Rare allergic reactions, including in people who handle psyllium powder occupationally.
Who should avoid it
Contraindicated with difficulty swallowing, known narrowing of the gut, or a sudden change in bowel habit lasting more than two weeks without a diagnosis. Suitable in pregnancy in most guidance, but ask if you are unsure.
Interactions with medicines
| Medicine or substance | What is described |
|---|---|
| Any medicine swallowed at the same time | Take other swallowed medicines at least 30 to 60 minutes before or after psyllium. A fibre gel sitting in the gut slows and can reduce absorption, which matters most for medicines with a narrow margin — levothyroxine, lithium, carbamazepine, digoxin. |
| Diabetes medicines and insulin | Psyllium slows glucose absorption from a meal. That is usually a good thing, but on insulin or glucose-lowering medicine it is a change to monitor for rather than to be surprised by. |
| Levothyroxine and thyroid treatment | Levothyroxine is the classic example of the timing problem: take it on an empty stomach and keep psyllium well away from that dose. |
The reverse view — start from the medicine rather than the plant — is in the medicine, food and alcohol interactions reference, and summarised for every herb on this site.
As a food
This one is also in the kitchen, so the nutrition figures are worth having next to the pharmacology: see the food data page for calories and nutrients per 100 g and per portion. Culinary amounts and medicinal preparations are different exposures, and the difference is usually the whole safety story.
Sources: European Medicines Agency — Committee on Herbal Medicinal Products (HMPC), European Union herbal monographs · NIH National Center for Complementary and Integrative Health — herb fact sheets · checked 2026-09-06
Frequently asked questions
What is psyllium (ispaghula husk) used for?
Constipation, and conditions in which easy defecation with a soft stool is desirable; also used to increase dietary fibre intake. Psyllium barely behaves like a drug at all: the husk is soluble fibre that absorbs many times its weight in water and forms a gel, which softens hard stool and firms loose stool at the same time. That two-way action is why it is used in irritable bowel syndrome as well as in constipation, and why it is usually the first thing to try before a stimulant laxative. Reviews of randomised trials also show a modest, consistent reduction in LDL cholesterol, which is unusual company for a herbal product. The safety rule is simple and absolute: always take it with a full glass of liquid and keep drinking through the day. Taken dry, or with too little fluid, it can swell in the throat or gut and cause an obstruction — that is what the warning on every pack is about, and it is why it should not be taken immediately before lying down.
Does psyllium (ispaghula husk) work?
Graded A here: A European Union herbal monograph carries a well-established-use indication for a defined preparation, meaning the regulator accepted clinical evidence. Sudden severe abdominal pain, suspected obstruction, or a new unexplained change in bowel habit. Fibre added on top of an obstructed bowel makes things worse, not better.
How much psyllium (ispaghula husk) should I take?
This reference does not print gram figures, because they do not transfer between preparations of different extract strength. What can be said honestly is the form and the duration: Husk or powdered husk in sachets, granules and capsules. Whole-seed preparations behave differently from husk. Suitable for continued use, unlike stimulant laxatives — but symptoms that persist beyond a couple of weeks still deserve a look.
What are the side effects of psyllium (ispaghula husk)?
Bloating and wind in the first days, easing as the gut adapts. Rare allergic reactions, including in people who handle psyllium powder occupationally.
Does psyllium (ispaghula husk) interact with medicines?
Yes — documented for Absorption timing, Diabetes medicines, Levothyroxine. Each one is described on this page, with a link to the medicine-side reference where one exists.
Others in digestion, bloating and the bowel
Peppermint
Symptomatic relief of minor spasms of the gastrointestinal tract, flatulence and abdominal pain, especially in irritable bowel syndrome, for gastro-resistant oil capsules; the leaf is registered for mild digestive complaints.
Caraway
Mild spasmodic gastrointestinal complaints including bloating and flatulence.
Ginger
Prevention of nausea and vomiting in motion sickness, and mild digestive complaints such as bloating.
Fennel
Mild spasmodic gastrointestinal complaints including bloating and flatulence; and as an expectorant in cough associated with a cold.
Turmeric
Relief of digestive disturbances such as a feeling of fullness and flatulence.
Liquorice
Digestive complaints including burning sensation and dyspepsia; and as an expectorant in cough associated with a cold.
Keep the whole list in one place
TempoLife logs supplements alongside food, sleep and how you actually felt — so the answer to "what are you taking?" is a screen, not a guess.