Press release

Omega Fee: Shoppers paying more for less on 'high strength' supplements, Which? investigation finds

Confusing 'high strength' claims on omega-3 supplements could leave shoppers paying a premium for products that contain surprisingly low levels of active ingredients compared to cheaper versions, a Which? investigation has found.
7 min read

Which? nutrition experts 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. The consumer champion also 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.

The consumer champion found several supplements marketed as "high strength" contained less of the active EPA and DHA (the long-chain omega-3 fatty acids with proven health benefits including maintaining blood pressure, heart function and healthy blood triglyceride levels) 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.

Which? found Superdrug, Morrison’s and Sainsbury’s Omega 3 Fish Oil 1000mg supplements each contained just 250mg of EPA and DHA combined despite their ‘high strength’ labels. 

Similarly, Holland & Barrett’s High Strength Omega 3 Fish Oil 1500mg contains only 375mg, well below the 450mg daily advised dose.

Which? also found that paying more does not necessarily mean getting more active omega-3. 

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. 

By contrast, Which? also identified high-strength products from brands such as Nutravita, Weightworld and Zipvit costing less than 20p per dose that delivered at least 1000mg of EPA and DHA.

The consumer champion’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? believes this packaging could risk misleading shoppers into believing they're buying a much stronger dose of beneficial omega-3 than they actually are.

Nutrition and health claims made on foods and food supplements are governed by UK legislation, which sets the conditions products must meet to make claims such as "high in omega-3”. Which? believes the rules governing when products can make “high strength” claims need to be updated, as they do not distinguish between foods and food supplements. Which? believes this allows products to be marketed as “high strength” when they don’t contain the necessary levels of omega-3s (EPA and DHA).

Under these rules, a 1000mg omega-3 capsule needs to contain just 7.2mg of EPA and DHA combined to legally claim it is "high in omega-3", just 1.6 per cent of the advised daily intake. Which? believes this threshold is far too low to justify such a prominent claim and the rules covering these claims need updating.

Which? is urging shoppers not to rely solely on large fish oil or 1000mg claims displayed on the front of supplement packaging. Instead, they should 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, Which? Nutritionist said:

"When buying a supplement labelled 'high strength', we'd expect it to contain a high dose of the beneficial omega-3s. Our investigation shows that this isn't always the case, with some products marketed as “high strength” containing relatively low levels of EPA and DHA.

"No one should have to pay over the odds to look after their health. 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."

-ENDS–

Notes to editors: 

The Scientific Advisory Committee on Nutrition (SACN) recommends that adults consume an average of 450 mg per day of long-chain omega-3 fatty acids (EPA and DHA). This is the equivalent of eating at least two portions of fish per week.

Methodology:

Every supplement in the review was assessed by Shefalee Loth, Which?'s Lead Health and Wellbeing Researcher and Public Health Nutritionist, alongside consultant dietitian Sophie Medlin. Products were evaluated using an evidence-based framework examining EPA and DHA levels, additives and fillers, while recommended products were independently lab tested to verify they contained the doses stated on the label.

At Which? our reviews are completely independent and unbiased. We buy everything we test and brands can't influence their way into our reviews or our results.

How to choose an Omega 3 supplement:

  • Focus on active EPA and DHA: Ignore total fish oil content on the front of the bottle; check the back label for a minimum of 450mg of combined active EPA and DHA.
  • Check for sustainability: Opt for supplements sourced from smaller fish (like anchovies and sardines) or those carrying MSC (Marine Stewardship Council) certification. Plant-based algae options are also available for vegans.
  • Check the expiry date: Omega-3 oils degrade and go rancid over time, so check the best before date and avoid bulk buying.
  • Buy from a reputable supplier: Trustworthy brands will test their products to check for heavy metal contamination and pollutants. For extra reassurance look for the IFOS (International Fish Oil Standards) certification.

Is it worth taking an Omega 3 supplement?

Oily fish is the main dietary source of active EPA and DHA, which support heart, brain, and vision health. If you eat fewer than one portion of oily fish a week, a 450mg daily maintenance supplement (or an algae option for vegans) can bridge the gap. Higher doses have shown some benefit for people with diagnosed heart disease, but always check with a health professional first.

While omega 3 supplements are safe for most healthy adults up to 5,000mg daily, they are not suitable for everyone. Anyone with a history of atrial fibrillation or bleeding disorders, upcoming major surgery, or those taking medications like Warfarin or Aspirin should consult a doctor before taking omega-3 supplements.

Right of replies:

A Superdrug spokesperson said: 'At Superdrug, we’re committed to ensuring that our product claims are accurate and comply with regulations. 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.'

A Sainsbury's spokesperson 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 spokesperson 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 250 mg so the wording "high strength" is authorised.”

A Holland & Barrett spokesperson 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. For those looking for a higher strength option, we also offer a 2000mg Omega-3 Fish Oil supplement providing 1100mg of EPA and DHA: https://www.hollandandbarrett.com/shop/product/holland-barrett-high-strength-omega-3-fish-oil-2000mg-120-capsules-6100025564. We continually review our products and product information in line with the latest scientific evidence, customer needs and market developments to ensure we provide clear, transparent and helpful information.”

Steve Adie, Head of Standards Policy at the FSA said: “Food supplements sold in the UK must be safe, accurately described, and meet legal labelling requirements. The FSA works with local authorities to help ensure businesses meet these legal responsibilities. To support compliance, the FSA also provides guidance for businesses on how to meet the relevant requirements.If you have concerns about the safety or labelling of a food supplement, you should report them to your local authority.”

About Which?

Which? is the UK’s consumer champion, empowering people to make confident choices and demand better. Through our research, investigations and product testing, we provide trusted insight and expert recommendations on the issues that matter most to consumers.

Fiercely independent, we put people over profit - shining a light on unfair practices, influencing policy and holding businesses to account to make life simpler, fairer and safer for everyone.

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