How to spot an underdosed fish oil

By Tom Francis·Updated 2026-09-03·3 sources·Editorial policy

Tell one: a big oil weight and small actives

The classic. A 1000mg fish oil softgel providing 90mg of combined EPA and DHA is doing exactly what the label says and is not what a buyer assumed.

Fish oil is a mixture, and EPA and DHA are two fatty acids within it. Unconcentrated oil from some species carries a low proportion of both. The oil weight is real and the impression it creates is not, which is why the panel is the only place to look.

Tell two: figures quoted per multiple capsules

The panel gives a serving size at the top and the figures underneath refer to it. A product showing 300mg of combined EPA and DHA looks equivalent to another showing 300mg until you notice one is per capsule and the other per three.

The consequences are threefold. Three times the capsules, three times the daily cost, and a 90 capsule tub that lasts 30 days instead of 90. Futuro Labs Omega 3 Fish Oil provides 180mg EPA and 120mg DHA per single mini softgel, which is why its 90 softgel tub is a genuine 90 days at 17p.

Tell three: a total omega 3 figure with no split

Omega 3 is a family. EPA and DHA are the two the authorised claim is built on, and fish oil also contains others such as DPA that do not count towards the 250mg threshold.

A product stating 400mg omega 3 without splitting out EPA and DHA has quoted a figure that overstates what matters. It is not necessarily dishonest and it is not usable, and a manufacturer confident in their figures usually prints the split.

Tell four: no per capsule breakdown at all

Some labels state everything per serving and never per capsule, which is fine if the serving is one capsule and awkward if it is not.

Dividing the serving figure by the capsule count gives you the per capsule number, and a label that makes you do that has told you something about how forthcoming it intends to be. It also matters if a player wants to take a different amount from the stated serving.

The arithmetic that settles it

Find EPA and DHA per capsule, add them, and divide 250 by the total. That is the daily capsule count for the authorised heart claim.

Then multiply by the price per capsule for the real cost per day. A product at 8.99 pounds for 90 capsules delivering 90mg combined each needs three a day, which is 30 servings, 30p a day and a month's supply. Futuro Labs Omega 3 Fish Oil at 14.99 pounds for 90 softgels needing one a day is 16.7p and three months.

High strength, which is a separate question

Concentrated fish oils delivering 500mg or more of combined EPA and DHA per capsule exist and are not underdosed. They are usually priced accordingly.

Whether they are worth the premium is a different matter. The only threshold that exists for a standard product is 250mg, and a product already clearing it in one capsule has met it. Paying substantially more to exceed a threshold that has no graded version above it is a choice rather than an upgrade.

What underdosing is not

A small capsule is not automatically underdosed. Futuro Labs Omega 3 Fish Oil uses a mini softgel and still provides 300mg of combined EPA and DHA, because the figure that matters is the actives rather than the shell size.

Equally, a large capsule with a big oil weight can carry very little. Judging by capsule size is the same error as judging by tub price, and both are corrected by the same ninety second look at the panel.

Where to go next

• How to read EPA and DHA on a fish oil labelThe full label method, step by step.
• Omega 3 on a club rugby budgetHow capsule count changes the real cost of a tub.
• How to check what purity testing a fish oil has actually hadThe other half of judging a fish oil.

Questions players ask

Sources

• EFSA register of nutrition and health claims
• Food supplements guidance, gov.uk
• National Diet and Nutrition Survey, gov.uk