Omega-3 (EPA and DHA) forms for supplement manufacturing

How the forms compare

There is no single best form of omega-3 for every product. EPA and DHA are the two long-chain omega-3 fatty acids that supplement labels declare. The real choice is between oils that differ in EPA-to-DHA ratio, binding form, source and concentration. The label claim and the finished format decide which oil fits.

EPA has 20 carbon atoms and five cis double bonds. DHA has 22 carbon atoms and six. Both belong to the fatty acids and lipids category.

The CAS numbers shown for this page identify EPA and DHA as free fatty acids. Commercial oils carry them mostly bound as triglycerides, ethyl esters or phospholipids. Each binding form behaves differently in processing.

Three differences matter most in a formulation. The first is concentration: a concentrate delivers the same label claim in less fill mass. The second is the EPA-to-DHA ratio, which is fixed by the source and the concentration process. The third is the basis of the declared content.

Specifications express EPA and DHA in mg per gram on a stated basis: as triglyceride, as ethyl ester or as free fatty acid. The label calculation must use the same basis throughout. The fill needed per serving is the label claim divided by the specified content per gram.

Choosing the best form of omega-3 for a product

• Label claim per serving. High claims per softgel need a concentrated ethyl ester or re-esterified triglyceride. A natural-triglyceride oil needs more fill mass, or more units, for the same claim.
• Format. Liquid oils go into softgels, commonly with a gelatin shell, or into sealed hard capsules. Tablets and powders need a microencapsulated oil. Gummies need an emulsified or encapsulated oil that tolerates the cooking step.
• Oxidative stability. Both acids oxidise readily, and DHA carries one more double bond than EPA. Handle oils under nitrogen, away from light and heat. Antioxidants such as tocopherols are usual; see vitamin E forms.
• Taste and odour. Oxidised marine oil has a strong odour. Liquids are usually flavoured, and softgels may be coated to limit aftertaste.
• Source. Fish and krill oils trigger allergen labelling. Microalgal oils give a fish-free source, most of them DHA-rich. Confirm any certificate a product requires against the specification of the lot offered.
• Combinations. Oil-soluble actives such as vitamin D or coenzyme Q10 dissolve or disperse in the oil fill. Check their stability with the chosen antioxidant system.
• Cost per milligram. Concentrates cost more per gram of oil but fewer or smaller units carry the claim. Compare offers per mg of EPA plus DHA on the same basis.
• Regulatory status. Krill and microalgal oils need a novel-food check; for fish oils, confirm the status of the specific oil and any concentration process. See the next section.

The certificate of analysis states EPA and DHA content with its basis. It also gives oxidation parameters such as peroxide value, anisidine value and TOTOX, and contaminant results such as dioxins and PCBs. SoleChem sends the specification sheet and certificate of analysis with its quote; state the source, binding form and concentration you need in the quote form.

EU regulatory status

EPA and DHA are neither vitamins nor minerals. They are therefore not listed in Annex I or Annex II of Directive 2002/46/EC. The Directive still applies to food supplements that contain them, as substances with a nutritional or physiological effect. Rules on such substances are largely national, so requirements differ by member state.

Member states may set their own maximum amounts or notification rules for EPA and DHA in supplements. Check the rules of each target country with its competent authority; see maximum levels by EU country.

Novel-food status depends on the source. Oils from krill and from certain microalgae are covered by entries in the Union list of novel foods under Regulation (EU) 2015/2283. Each entry sets a specification and conditions of use that the material and the product must meet. The status of concentrates and other sources must be checked case by case; see the novel food guide.

Claims about omega-3 content or EPA and DHA fall under Regulation (EC) No 1924/2006. Authorised wording and conditions of use are in the EU Register of nutrition and health claims. The health claims guide explains how the Register works.

Fish and crustaceans are allergens listed in Annex II of Regulation (EU) No 1169/2011. Antioxidants added to the oil are food additives under Regulation (EC) No 1333/2008. The labelling guide covers how the EPA and DHA amounts appear on the pack.