The consumer group Which? has published an analysis of six fibre supplements sold in the UK and found that two of the six deliver less fibre per dose than a cheap bowl of porridge. The investigation, by Which? senior researcher and registered nutritionist Charlotte Phillips, appeared on 8 October 2026. It priced each product per daily dose and set it against a food carrying a comparable amount of fibre, using Tesco standard retail prices as of 5 October 2026. Novomins Fibre Gummies, labelled as providing 4,000mg of fibre, worked out at 66p a dose for 4g of fibre. Which? put the same 4g in a 50g bowl of porridge oats at around 4p. Wellthy by Boots Daily Fibre High Strength Capsules came to 42p a dose for 2g, which Which? matched to a small sweet potato at 35p. Holland & Barrett psyllium husk capsules were 60p a dose for 2.2g.
Why fibre packs carry vitamin claims
Which? described a marketing practice it called fairy dusting. Very few nutrition and health claims about fibre are authorised for use in Great Britain, so some brands add a nutrient that does carry an authorised claim and print that claim on the front of the pack. Which? gave Novomins Fibre Gummies as its example. The product contains vitamin B12 and vitamin D2, which permits on-pack claims about the immune system and normal energy-yielding metabolism. Neither claim concerns the fibre. Authorised wording in Great Britain comes from the GB Nutrition and Health Claims Register; Northern Ireland continues to follow the EU register. Which? also questioned a "years of research and testing" line used by Biomel, which it priced at £1 per scoop for 4.7g of fibre.
What this means for your supplement routine
Fibre per dose and cost per dose are both printed on the pack or calculable from it, and the Which? table shows how far apart products sit. Bulk Fibre Plus came to 22p a dose for 5.1g, while Myota Gut Health Fibre Blend was £1.66 a dose for 9.8g. Government guidelines, as reported by the NHS, say dietary fibre intake should rise to 30g a day, and the NHS notes most adults average about 20g. Which? said just 4% of the population reaches 30g through diet, citing the National Diet and Nutrition Survey 2019 to 2023. Phillips summarised her advice to readers as "Food first, supplement second". The arithmetic Which? used here, cost against nutrient per serving, works on anything in the full supplement catalogue.
How Perqen members save
Perqen shows member and non-member prices side by side on every product, so the cost per dose is visible before checkout rather than after. Perqen membership is £4.99 a month or £29.99 a year.
This article reports published news and research and is for information only. Food supplements are not a substitute for a varied diet or medical care, and no product mentioned is intended to diagnose, treat, cure or prevent any disease. Speak to your GP or pharmacist before changing what you take, especially if you are pregnant, breastfeeding, or taking prescribed medicines.