Omega-3: the big number on the box is not the one to look at

You are looking at two boxes of omega-3.

The first says: 1,000 mg.

The second: 600 mg.

Which one provides more useful omega-3?

There is no way to know.

That is the little trap in this category: the most visible number can be the least useful one.

First reflex: ask “1,000 mg of what?”

A capsule can contain 1,000 mg of oil without containing 1,000 mg of EPA and DHA.

EPA and DHA are the two long-chain omega-3 fatty acids that people generally want to quantify. The rest of the oil may contain other fatty acids.

To compare two products, look for three lines:

That already tells you far more than “1,000 mg of oil” printed in large type.

EPA and DHA are not two names for the same thing

They belong to the same family, but their structures differ and they do not have exactly the same physiological roles.

Two formulas providing the same total amount of EPA + DHA can therefore have very different profiles.

The useful question becomes: how much of each, and why this ratio?

Second level: in what lipid form?

EPA and DHA can be supplied in different forms, including triglycerides, re-esterified triglycerides, ethyl esters and phospholipids.

These forms do not follow exactly the same digestive pathway. Several human trials have therefore compared their bioavailability.

In 2010, a trial in 72 volunteers found, under the conditions tested, higher bioavailability with re-esterified triglycerides and lower bioavailability with ethyl esters compared with natural fish oil.

But a 2015 trial, using similar doses of EPA and DHA, found no significant difference in its primary endpoint between ethyl-ester fish oil, triglyceride fish oil and krill oil.

So no, the word “triglyceride” alone is not enough to crown a winner.

Your meal can change the result

Dietary fats stimulate the mechanisms that help digest and absorb lipids. The composition of a meal can therefore alter the absorption of some omega-3 forms.

In a classic human study comparing low-fat and high-fat meals, absorption of EPA and DHA in ethyl-ester form increased substantially with the high-fat meal.

That matters when a brand claims “twice as well absorbed”.

The next part of the sentence should be: compared with what, at what dose, with what meal, and measured how?

Third level: concentration and number of capsules

Two capsules of the same size can provide very different amounts of EPA + DHA.

A more concentrated oil can make it possible to reach the intended intake with fewer capsules.

This is not only about convenience. A formula you actually take every day has a better chance of being useful than a formula that looks perfect on paper but is abandoned after ten days because it requires six capsules and three reminders.

Then there is the quality you can barely see: oxidation

EPA and DHA are highly unsaturated. That structure makes them sensitive to oxidation.

The industry monitors peroxide value, para-anisidine value and TOTOX, among other indicators, to assess the oxidative state of an oil.

A fishy taste can be a sensory clue, but it is not a certificate of analysis. Packaging, storage, antioxidants, residual oxygen and finished-product stability matter too.

In other words, an excellent oil entering the factory can become an average product if its stability is poorly controlled afterwards.

Seven questions to ask before buying

Premium quality is often in the small print

A big number is easy to photograph.

A stability analysis or oxidation test, much less so.

But when assessing an omega-3, that is often exactly where the difference lies between an appealing formula and one whose quality is genuinely controlled.

With omega-3, the right reflex is not to look for the biggest number. It is to understand what that number is measuring.