Psyllium husk, known in India as isabgol, is the outer coating of seeds from the Plantago ovata plant. Most of the world’s psyllium is grown in India, and it’s the main ingredient in fibre supplements such as Metamucil. It’s one of the most studied and affordable fibre supplements available.
What psyllium husk does
Psyllium is a soluble fibre. When it mixes with water it forms a thick gel, which softens stool, slows digestion and helps you feel full.
Benefits with good evidence
- Constipation: it softens and bulks up stool so it passes more easily. It’s often the first thing pharmacists suggest.
- Diarrhoea: by soaking up excess water, it can also firm up loose stools.
- Cholesterol: taken daily, psyllium can lower LDL (“bad”) cholesterol by a modest amount. In the US, the FDA allows a heart-health claim for psyllium as part of a diet low in saturated fat and cholesterol.
- Blood sugar: taken with meals, it can reduce blood sugar spikes after eating.
- Feeling full: it may help you feel fuller and eat a little less, which can support weight management. See fibre for weight loss.
How to take it
- Start low: 1 teaspoon (about 3 to 5 g) once a day, and build up over 1 to 2 weeks to 1 to 2 doses a day. Follow the product label.
- Always mix with a full glass of water (at least 240 ml / 8 oz) and drink it straight away, before it thickens. Then drink plenty of fluids through the day.
- Take medicines 2 hours apart from psyllium, as it can reduce how well they’re absorbed.
- For feeling full, take it 20 to 30 minutes before a meal.
Side effects
- Wind, bloating and tummy cramps, especially at first. Building up slowly helps.
- Choking or blockage risk if taken without enough water. Never take it dry.
- Rarely, allergic reactions. Stop and get help if you have trouble breathing or swallowing, or a rash.
Who should check with a doctor first
- Anyone with difficulty swallowing, a narrowed bowel or a history of bowel blockage
- People with diabetes, as it can lower blood sugar after meals
- Anyone taking regular medicines, because of the absorption issue
- Children
See a doctor if
You have a sudden change in bowel habits lasting more than 2 weeks, blood in your stool, unexplained weight loss, or severe tummy pain.
Frequently asked questions
Is isabgol the same as psyllium husk?
Yes. Isabgol is the Hindi name for psyllium husk.
Can I take psyllium every day?
Yes. It’s safe for daily long-term use for most adults, as long as you drink enough water.
When is the best time to take psyllium?
Any time that suits you, keeping it 2 hours away from medicines. Before meals may help with fullness and blood sugar. At bedtime with water is common for constipation.
Does psyllium help you lose weight?
It may help a little by making you feel fuller, but it works best as part of a balanced diet with plenty of other fibre-rich foods.
Related: How long does Dulcolax take to work?
More in our Digestive Health guide: all our articles and products on this topic in one place.
This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Supplements are not evaluated by the FDA to diagnose, treat, cure or prevent any disease.
