Is your 'high-strength' omega 3 supplement a rip-off?

Supplements labelled 'high strength' may contain the same or less omega 3 than cheaper standard versions, Which? research has found, leaving consumers out of pocket and under-served.

We analysed 24 popular omega 3 fish oil supplements, including big brands and own-brands from high street retailers such as Boots, Tesco and Superdrug and found big variations in omega 3 levels between products.

Some supplements labelled as ‘high strength’ contained less omega 3 fish oils than the recommended guideline daily amount - and the same as or less than products not labelled ‘high strength’, despite costing more. 

Levels of combined omega 3s EPA and DHA in 'high-strength' supplements ranged from just 250mg to 1764mg, while in the standard ranges (that don't claim to be high strength on the pack) they varied from 244mg to 660mg.

We also found front-of-pack claims around total fish oil content that make it hard to know what you're really getting.

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Big variations in 'high-strength' Omega 3 supplement doses

Most brands quote the total fish oil content prominently on the front of the pack. This is usually an impressively high number, such as 1,000mg or 1,500mg. 

If you spot this, and the label ‘high strength' emblazoned above it, you might expect to be getting at the very least the recommended daily amount of omega 3s.

But we found this isn't always the case, and the amount of actual 'active ingredients' - aka the omega 3 fish oils that have been shown to be beneficial for health, can vary significantly between products. 

One 'high-strength' supplement might give you seven times as much as another, while a cheaper version not labelled 'high strength' might contain the same amount of omega 3s - or more - than a 'high-strength' version.

What really matters is the concentration of EPA (Eicosapentaenoic acid) and DHA (Docosahexaenoic acid). These are long-chain omega 3 fatty acids with proven health benefits, including maintaining blood pressure, heart function and healthy blood triglyceride levels. 

Some brands state these levels on the front of the pack, but not all.

Products that we think shouldn't be classed as 'high strength' include these from Holland & Barrett, Morrisons, Sainsbury's and Superdrug:

Superdrug’s 'high-strength' supplement contains the same level of EPA and DHA as Boots Omega 3 fish oil 1,000mg (250mg). But Boots' supplement costs 9p per dose and doesn't claim to be high strength, whereas Superdrug’s costs 13p.

Similarly, of the four own-brand supermarket omega 3 supplements we reviewed - which are nutritionally identical - two are labelled as 'high strength', and two aren't. 

All contain 1,000mg total fish oil and 250mg EPA and DHA. But if you buy Sainsbury’s 'high-strength' version (14p per dose) you'll pay twice as much as for an identical product at Asda and Tesco (both 7p, and not labelled high strength). 

Holland & Barrett’s 'High Strength' Omega 3 fish oil 1,500mg costs 27p per daily dose but contains just 375mg of EPA and DHA. This is only 75mg more than its standard pack, which costs 22p per daily dose.

Meanwhile, our analysis revealed three Great Value high strength omega 3 supplements that costs less than 20p per dose and contain at least 1,000mg combined EPA and DHA.

Why we think supplement rules could be improved

Although there’s not an official recommended daily intake of EPA and DHA, the Scientific Advisory Committee on Nutrition (SACN) advises people to consume 450mg of EPA and DHA (total) a day. This is the amount that you would average daily if you consumed the recommended two portions of fish a week (one oily). 

None of the above ‘high-strength’ supplements meets this guideline amount in their recommended dose of one capsule.

Despite this, when we checked, we found that the products do technically comply with regulations that govern nutrition and health claims made on foods (which includes food supplements). These state that if a product contains at least 80mg of EPA and DHA per 100g or 100 kcals, it can be labelled as 'high omega-3'. 

This is what Superdrug, Sainsbury's and Morrisons told us when we queried it with them. Holland & Barrett, however, said there was no 'currently legal or industry-wide definition of what constitutes 'high strength' omega-3', and it uses the term to help customers distinguish between products in its range.

We think this rule doesn't really make sense when applied to supplements vs food products due to the weight differences and the way you consume them. It means that an omega 3 supplement that contains 1,000mg (1g) of fish oil would only need to contain 7.2mg of omega 3s to be labelled as 'high strength'. This is just 1.6% of the advised daily intake. 

Sue Davies, Head of Consumer Rights and Food Policy at Which? says:

'Our analysis shows yet again how confusing claims made on some food supplements can be - even when bought from leading high street names.  It also shows how the law hasn't always kept up with the way that products are now offered and how people are buying them.' 

What to look for when choosing an omega 3 supplement

Focus on the EPA and DHA content. Ignore that big fish oil number quoted on the front of the pack labelling. Ideally, products should clearly state EPA and DHA content on the front of the pack as well as overall fish oil content.

If a product doesn't do this, make sure you check the nutrition information on the back where it should be listed, and pay attention to the breakdown of EPA and DHA per dose. 

It's also worth checking the recommended daily dose, as it’s often two or three capsules. If you miss this, you can't compare prices properly, so you need to ensure you're comparing like with like. 

See our reviews of the best omega-3 supplements for our recommended options, whether you're after a regular dose or a high-strength version.

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.'

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Why it's worth doing your research before buying any supplement

As well as omega 3 supplements, we've assessed hundreds of other popular food supplements this year, including multivitamins, magnesium, probiotics, vitamin D, B12 and iron. 

The more we've looked into the supplements market, the more we've found a minefield of confusing claims and labelling that make it hard to compare and know if you're buying the right thing for your needs.

Years of experience in this field mean we know what to watch out for. For each supplement category we review, we start by assessing which ingredients are the most beneficial and at what doses, based on the latest quality research evidence available. We then develop an assessment framework to score popular supplements against to find the best. 

As part of this, we'll check if the key nutrients are present in their most readily absorbable form, if the dose is appropriate and if there are any unnecessary fillers, bulkers or extras. Any supplements we plan to recommend are then sent to an independent lab to check they contain the dose claimed. 

We've found that the biggest brands and priciest supplements aren't necessarily the best. In some cases, a basic own-brand can be better.  We've also found some products where the dose claimed on packaging doesn't match what's in the actual supplement when we lab test it - so you could be getting too much or too little of a nutrient.   

We've also looked into the wider supplements market, as part of our mission to make the landscape safer for shoppers - uncovering illegal vitamin supplements for sale and supplements with unsafe doses being sold on the high street and on online marketplaces.

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. Find out more about how Which? is run.