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How to read an omega-3 label

The big number on an omega-3 pack is the oil weight. Add the EPA and DHA in 1 serving to compare packs; if the label gives a percentage, work out the milligrams first.

KiloCare Team · · 4 min read · How we write and review

A small amber bottle on its side beside a magnifying glass over a blank card on a light oak table.
A closer look at an omega-3 bottle before you buy.

Find EPA and DHA in milligrams

On the back of the pack, look for a line for EPA and a line for DHA, each in milligrams (mg). Add them together. That sum is the EPA and DHA the label gives.

A plain white supplement bottle with its back label facing out: a large block of lines at the top, two shorter lines below it and one small line near the bottom, beside a dish of amber softgels.
  1. Oil weight the big number, the whole oil
  2. EPA add this line
  3. DHA and this one
  4. Serving size how many capsules the figures cover

The NIH (US National Institutes of Health) says omega-3 supplements vary widely, so check each label for which omega-3s it holds and how much.[1]

The oil weight is not the omega-3

On Capsule A below, 1,000 mg of fish oil gives 300 mg of EPA and DHA. Here are 2 real labels, shown without brand names. The figures are the makers' own.

Capsule A is a fish oil sold in India. Each capsule lists:

  • 1,000 mg of fish oil
  • 180 mg of EPA
  • 120 mg of DHA

Add the 2 omega-3 lines, and 180 plus 120 makes 300 mg of EPA and DHA in each capsule. The rest of the oil, 700 mg, is other fats, and the label does not say which. The NIH gives these same figures for a typical fish oil capsule.[1]

Capsule B is an algal oil sold in Europe. Each capsule lists:

  • 834 mg of algal oil
  • 250 mg of DHA
  • 125 mg of EPA

Together that is 375 mg of EPA and DHA, about 45% of the stated oil weight. The oil is a blend with sunflower oil.

Side by side, the oil weight is the bigger number on both labels, as on the NIH's typical capsule.[1]

Oil weight and EPA plus DHA in 1 capsule
Capsule A fish oil1000 mg
Capsule A EPA and DHA300 mg
Capsule B algal oil834 mg
Capsule B EPA and DHA375 mg

GOED, an omega-3 industry body, notes that makers can calculate the milligrams of EPA and DHA in more than one way.[2] A difference of a few milligrams may come from the calculation. A large difference, such as a capsule with 75 mg against one with 300 mg, is a real difference between packs.

When the label gives a percentage

Some labels give no milligrams of DHA. They give an ingredient weight and the share of it that is DHA. Take a made-up pack whose label reads "algal DHA (providing 20% DHA) 500 mg".

The label may not say what the percentage refers to. Read it as a share of the ingredient weight, and treat the answer as an estimate.

Calculate the DHA on your pack

Multiply the ingredient weight by the percentage, then divide by 100. For the made-up pack, 500 times 20, divided by 100, gives 100 mg of DHA.

Type both numbers from your pack. Use a percentage of 100 or less.

If a label gives DHA only, compare packs on DHA. The EPA is not stated, which is not the same as none.

Serving size

Find the line for serving size. On Capsules A and B, one serving is 1 capsule. If a serving is 2 capsules, the milligrams on the panel are for both together. Divide by 2 for one capsule.

A pack labelled "NUTRACEUTICAL" must give a recommended usage. It may also carry the warning "not to exceed the stated recommended daily usage".[3] Read those lines with the serving size. Whether you need more omega-3 than your food gives is a separate question, covered in how much omega-3 adults need.

5 things to check before you buy

  1. The category word. The pack says "NUTRACEUTICAL" or "HEALTH SUPPLEMENT". Either way it must say "NOT FOR MEDICINAL USE" and tell you to store it out of reach of children.[3]
  2. EPA and DHA in one serving. Add the 2 lines, and check how many capsules make a serving.
  3. The licence, batch and dates. The pack must show the logo and licence number of FSSAI, India's food safety regulator, and a batch or lot number. It must also show the date it was made or packed, and an expiry or use-by date.[4]
  4. The storage line. A review of fish oil supplements says that light, heat and air make the oil go stale (oxidise), even at room temperature. Added antioxidants slow this but do not stop it.[5] The pack must give storage instructions when its date depends on them.[4] Follow them, keep the lid closed, and keep the pack away from heat and sunlight.
  5. The source and the form. Look for the oil the omega-3 comes from: fish, krill, cod liver or algae. Our article on kinds of omega-3 supplement explains each one, and what the form on a label means.

Ask your doctor before you take an omega-3 supplement if you take a blood thinner or any medicine regularly, are pregnant or breastfeeding, or are buying it for a child.

If you have a fish or shellfish allergy, ask your doctor before you take fish or krill oil.

Do not take more than the pack says.

Medical disclaimer: This article is general information. It does not replace advice from your doctor about your own health.

Common questions

No. The oil weight is a bigger number than the omega-3. Read the EPA line and the DHA line on the back of the pack, and add them.

Multiply the ingredient weight by the percentage, then divide by 100. The label may not say what the percentage is a share of. Treat the answer as an estimate.

FSSAI's rules allow a tested sample to fall only a little below the amount declared on the label. A large gap between two packs is a real difference.

Sources

  1. National Institutes of Health, Office of Dietary Supplements. Omega-3 fatty acids: fact sheet for health professionals [Internet]. National Institutes of Health; 2025 Aug 22 [cited 2026 Oct 23]. Available from: ods.od.nih.govCited atSources of omega-3s, Dietary supplementsSources of omega-3s, Dietary supplementsSources of omega-3s, Dietary supplements
  2. Global Organization for EPA and DHA Omega-3s. GOED monograph, version 9.1. GOED; 2026 Jul 23. Available from: goedomega3.comCited atDefinitions, p. 1; Fatty acids, pp. 2-3
  3. Food Safety and Standards Authority of India. Food Safety and Standards (Health Supplements, Nutraceuticals, Food for Special Dietary Use, Food for Special Medical Purpose, Functional Food and Novel Food) Regulations, 2016. New Delhi: FSSAI; 2021 Sep 29. Compendium Version-I. Available from: fssai.gov.inCited atReg 7(4)(iii)(d), (e), pp. 13-14Reg 6(3)(iii), pp. 11-12; Reg 7(4)(iii), pp. 13-14
  4. Food Safety and Standards Authority of India. Food Safety and Standards (Labelling and Display) Regulations, 2020: Compendium Version-VIII. New Delhi: FSSAI; 2025 Sep 9. Available from: fssai.gov.inCited atReg 5(7), 5(9), 5(10)(a), pp. 15-16Reg 5(10)(c), p. 17
  5. Albert BB, Cameron-Smith D, Hofman PL, Cutfield WS. Oxidation of marine omega-3 supplements and human health. Biomed Res Int. 2013;2013:464921. doi:10.1155/2013/464921. PMID: 23738326. Available from: pmc.ncbi.nlm.nih.govCited atSection 2, How stable are marine omega-3 supplements