'High-strength' Omega-3 sold on high street often no stronger than cheaper alternative, study

By SHAUN WOOLLER, EXECUTIVE HEALTH EDITOR Published: 00:01, 6 August 2026 | Updated: 00:01, 6 August 2026 Shoppers may be wasting money buying omega-3 supplements labelled as 'high-strength', an investigation reveals. Consumer group Which? found some pricier products contain less active ingredient than the recommended daily intake and less than cheaper alternatives. Its researchers assessed 24 omega-3 supplements against the Scientific Advisory Committee on Nutrition (SACN) guidance that people consume an average of 450mg of EPA and DHA per day. These are the long-chain omega-3 fatty acids with proven health benefits including maintaining blood pressure, heart function and healthy blood fat levels. The watchdog used 1,000mg of EPA and DHA as the benchmark for what an omega-3 product marketed as 'high strength' should contain, based on studies showing health benefits for certain groups at these levels. However, it found that several supplements marketed as 'high strength' contained less of the active EPA and DHA than the advised daily intake. In some cases, consumers could pay double the price for products containing no more active omega-3 than cheaper alternatives, it said. Which? found Superdrug, Morrisons and Sainsbury's Omega 3 Fish Oil 1000mg supplements each contained 250mg of EPA and DHA combined despite their 'high strength' labels. Sainsbury's charged 14p per dose for its high strength product containing 250mg of EPA and DHA, double the price of nutritionally identical products at Asda and Tesco. Similarly, Holland & Barrett's High Strength Omega 3 Fish Oil 1500mg contained just 375mg, well below the 450mg daily advised dose. Sainsbury's charged 14p per dose for its high strength product containing 250mg of EPA and DHA, double the price of nutritionally identical products at Asda and Tesco that each cost 7p per dose and do not claim to be high strength. Holland & Barrett's 1500mg 'high strength' supplement costs 27p per daily dose despite providing just 375mg of EPA and DHA, only 75mg more than its standard pack, which costs 22p per daily dose, Which? said. All of the retailers said their labelling complied with the Nutrition and Health claims register. By contrast, Which? found that brands including Nutravita, Weightworld and Zipvit cost less than 20p per dose while delivering at least 1000mg of EPA and DHA. The group's investigation found that many supplements display the total amount of fish oil in each capsule prominently on the front of pack, while the amount of beneficial active ingredients, EPA and DHA, is often only listed in smaller print on the back. Which? urged shoppers not to rely solely on large fish oil or 1000mg claims displayed on the front of supplement packaging and instead to check the combined EPA and DHA content on the back of the label to make sure they are getting the dose they need. Shefalee Loth, a nutrionist at Which?, said: 'Our research shows cheaper alternatives can often provide just as much – or even more – nutritional value while offering far better value for money, so it's worth checking the back of the pack rather than relying on front-of-pack claims.' Holland & Barrett's 1500mg 'high strength' supplement costs 27p per daily dose despite providing just 375mg of EPA and DHA. A Superdrug spokeswoman said: 'Our High Strength Omega 3 Fish Oil is classified as a food supplement and is subject to Regulation (EC) No. 1924/2006 on nutrition and health claims made on foods. 'The Regulation permits omega-3 claims where the product contains at least 80 mg of EPA and DHA combined. 'As this product contains 250 mg of combined EPA and DHA, the description 'High Strength' is considered appropriate and supported by the product's composition.' Sainsbury's said: 'We offer customers a range of supplements and vitamins which are all clearly labelled in line with requirements from the Nutrition and Health claims register.' A Morrisons spokesman said: 'We can confirm that the Morrisons product has been labelled correctly according to the regulation. 'Regulation 1924/2006 states that a claim that a food is high in omega-3 fatty acids, may only be made where the product contains at least 80 mg of the sum of eicosapentaenoic acid and docosahexaenoic acid. 'This product contains 250mg so the wording 'high strength' is authorised.' A Holland & Barrett spokeswoman said: 'There is currently no legal or industry-wide definition of what constitutes a 'high strength' omega-3 fish oil supplement. 'At Holland & Barrett, the term is used to help customers distinguish between the different strengths and formulations of omega-3 products within our range. 'It is intended to support product navigation rather than indicate compliance with an externally defined strength standard. 'The amounts of EPA, DHA and total omega-3 fatty acids are clearly displayed on our packaging and website, enabling customers to compare products and make informed choices.'