Psyllium is not so silly for easing constipation

The Irish Times
Health Supplement, p. 13
9 June 2009

DOES IT WORK? Psyllium and constipation

CONSTIPATION CAN be one of life’s bothersome but transitory conditions. Chronic constipation can become a source of much discomfort and pain. Data from France, Canada, the US and other countries have found that constipation is increasingly leading people to seek medical help. One survey found that GP visits for constipation had doubled over a recent seven-year period. In the US, millions of dollars are spent annually on over-the-counter laxatives.

Psyllium is a popular approach to relieving constipation by increasing bulk and fibre in the diet. The product is made from the seeds and seed husks of related plants from the plantain group, which is also part of the buckwheat family. The plant material is ground up and sold as a powder to be mixed with water. This forms a gel-like mucilage which cannot be digested and so passes through the gastrointestinal tract.

Evidence from studies 

A number of high-quality, controlled studies have examined psyllium’s effectiveness as a laxative. Most, but not all, have shown that psyllium is more effective than placebos in leading to regular bowel movements. One study found that psyllium was more effective than senna, another commonly used, natural laxative.

A group of small studies have found that a product containing both psyllium and senna was more effective than a number of other laxatives. So overall the evidence is that psyllium is an effective laxative for many people, although not for everyone.

An additional finding from some of the studies was that psyllium can lead to small, but statistically significant, reductions in total cholesterol and low-density lipoprotein (LDL) levels (so-called “bad” cholesterol). Reductions of 5-10 per cent were seen in most studies, especially when people also increased the amount of fruit and vegetables in their diet.

A smaller amount of evidence suggests that psyllium may also reduce blood sugar levels in people with diabetes, but not in those without diabetes. It is thought that glucose and cholesterol may become trapped within the psyllium fibre in the intestines and absorbed to a lesser extent. But the use of psyllium solely to reduce cholesterol or blood sugar levels has not become popular because diarrhoea is common in those who do not have chronic constipation.

Problematic aspects 

People can be allergic to psyllium seeds, and severe anaphylactic shock has been reported in a few cases. Anyone with allergies to common weeds should take small amounts of psyllium at first and check carefully for reactions, especially rashes.

Psyllium can also cause flatulence, diarrhoea and abdominal pain. Two years ago, the US Food and Drug Administration (FDA) removed its “safe and effective” status for psyllium granules and products intended to be chewed. They caused numerous cases of choking when people took them with insufficient water and the granules swelled in people’s throats. This ruling did not apply to non-granular powders or tablets.

Plenty of liquids should be taken with all psyllium products. Just as psyllium appears to slow the absorption of cholesterol and glucose, there are concerns it might interfere with the absorption of other medications. So these should not be taken at the same time as psyllium.


Chronic constipation causes discomfort and pain for many people. Psyllium mixed with liquids is an effective means of restoring regular bowel movements. However, people vary in how much they need and how much they can tolerate. One teaspoonful mixed with a glass of water or other liquid is usually recommended three times daily.

The long-term use of any laxative is not recommended. Increasing other fluids, the amount of fibre (fruit, vegetables) in the diet and daily physical activity can also help relieve constipation. If symptoms persist or become very painful, medical advice should be sought to check whether a more serious condition may have developed.

Back to Herbal Remedies list