EPA & DHA in OEM/ODM Supplements: Assay, Concentration & Fill Weight

Three quantities that should stay separate

Total oil weight, total omega-3 content, and individual EPA or DHA content answer different questions. An oil blend can contain fatty acids other than EPA and DHA, alongside other oil constituents. Start a formulation worksheet with separate columns for each quantity instead of using a single omega number throughout purchasing, development, and artwork review.

Decide whether the concept requires a specific EPA-to-DHA ratio, a combined amount, or separate declarations. A combined target alone leaves room for materially different compositions. Document which targets are mandatory before comparing concentrated oils against an unconcentrated ingredient with a lower price per kilogram.

Check the denominator on the certificate

Ask whether the supplier reports milligrams per gram of oil, a percentage by mass of the supplied material, or a relative chromatographic percentage of total fatty acids. These values should not be treated as interchangeable. Request the test method and reporting basis alongside the result; a neat percentage without its denominator is an incomplete calculation input.

A commercial description such as 18/12 is useful shorthand only after the specification explains it. Keep minimum specification values separate from the actual lot result and from a typical marketing value. The formulation team needs an agreed basis that does not depend on an unusually favorable sample certificate.

Work through a transparent example

Consider a hypothetical oil documented to contain 300 milligrams of EPA and 200 milligrams of DHA per gram as supplied. A 0.8-gram oil portion contributes 240 milligrams of EPA and 160 milligrams of DHA. The calculation is multiplication by the oil portion; it is not a recommendation for a consumer serving or a claim about any commercial grade.

If that oil is subsequently diluted with a carrier, calculate the active oil fraction first. An 80% active-oil mixture does not retain the original milligrams per gram of the undiluted ingredient. Record added flavor and antioxidant weights too, so the full fill weight and fatty acid contribution reconcile.

Compare quotations on the same basis

Compare ingredient cost at the proposed EPA and DHA contribution, not just at equal oil weights. Then add the effects of capsule count, fill capacity, processing, and packaging. A concentrated ingredient may change the required oil mass while introducing different physical or documentation requirements; the arithmetic alone does not decide the finished-product cost.

For a bottled liquid, review how a serving volume connects to mass through the relevant density measurement. Avoid copying a gram-based calculation directly into a milliliter-based label. Ask which temperature and density value the worksheet uses, particularly when comparing two different oil systems.

Close the loop with finished-product evidence

Use a finished-product method appropriate for the actual matrix, including carriers and flavors. Link the report to the formula revision and serving basis. Raw oil potency establishes an input assumption; it does not by itself demonstrate the composition of every filled capsule or bottle after manufacturing and storage.

An approved worksheet should remain with the ingredient specification. When a supplier changes concentration, reporting method, or grade, revisit the fill calculation and artwork together. This makes a future substitution visible before an equal-weight replacement silently changes the intended fatty acid amounts.

Explore relevant dosage forms

Compare manufacturing considerations for your intended product. Suitability depends on the complete formulation.

Common questions