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Field guide
Reading a Fish Oil Label: EPA + DHA, Not Oil Weight
"1,000 mg" on the front of a fish oil bottle is the weight of oil in a softgel. The reference values this site scores against are not written in milligrams of oil. They are written in milligrams of two fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), counted together. Those figures sit further down the Supplement Facts panel, and they are the ones to read.
Oil weight versus the EPA and DHA rows
A fish oil panel usually opens with the oil itself: "Fish Oil", "Purified Fish Oil" or "Fish Oil Concentrate". That is the weight of everything in the oil, including fatty acids that are not EPA or DHA. Beneath it, a well-disclosed panel lists EPA and DHA as separate rows, each with a milligram figure. Those two rows, added together, are the amount that counts.
A real example from our records: the panel for Evlution Fish Oil Softgels lists Fish Oil 1,000 mg, EPA 180 mg and DHA 120 mg per serving. That is 180 + 120 = 300 mg of EPA+DHA, under a third of the headline figure. The reference this site uses notes that a 1,000 mg softgel commonly contains about 300 mg EPA+DHA, so two bottles that both say "1,000 mg" on the front can still carry different amounts.
Check the serving size line too. If it says "2 Softgels", every figure beneath it is for two.
"Total Omega-3" is a different row
Many panels add a line such as "Total Omega-3 Fatty Acids". It is a wider group that can include omega-3 fatty acids other than EPA and DHA, so it is an upper limit on EPA+DHA, not a statement of it.
This site reads only the EPA and DHA rows. Where a panel prints EPA and DHA rows with no amounts, or only a total, the EPA+DHA amount is recorded as unknown. We do not estimate it from the total or from a typical ratio.
Cod liver oil labels that print only the oil
Some cod liver oil panels print a single line, "Cod Liver Oil 1,000 mg", with no fatty-acid rows. That states how much oil is in a serving and nothing about how much of it is EPA+DHA, and a gram of oil is not a gram of EPA+DHA. The site records that row by name and does not score it, because there is no figure to compare with the reference. A cod liver oil panel that does list EPA and DHA rows is read like any other fish oil panel.
The reference amount: 250 mg a day
The threshold is a population reference value for adults, not a personal recommendation:
| Ingredient | Reference amount | Source |
|---|---|---|
| EPA + DHA (combined) | 250 mg | EFSA Journal 2010;8(3):1461; FAO/WHO 2010, FAO Food and Nutrition Paper 91 |
The EFSA Panel on Dietetic Products, Nutrition and Allergies (EFSA Journal 2010;8(3):1461) set an adequate intake of 250 mg/day EPA+DHA for healthy adults. FAO/WHO 2010, Fats and fatty acids in human nutrition (FAO Food and Nutrition Paper 91), gives 0.250 g/day EPA+DHA for adults. Every threshold the site uses, with its citation, is on how we rate.
From label to cost per dosed serving
Fish oil sits in the site's health support category, where the value score is built on cost per fully dosed serving: what it costs to reach the reference amount using that product. It takes three steps.
- Price per serving: the store price divided by the servings in the package. Where a store sells more than one size of the same product, the lowest price per serving is used.
- Dose ratio: the serving's EPA+DHA divided by 250 mg, capped at 1. A serving at or above 250 mg has a ratio of 1; a serving with half that has a ratio of 0.5.
- Cost per dosed serving: price per serving divided by the dose ratio.
A worked example
The two bottles below are hypothetical, with round numbers chosen to show the arithmetic. They are not real products.
Bottle A costs $20.00 for 100 servings. Each serving lists EPA 90 mg and DHA 35 mg.
- Price per serving: $20.00 ÷ 100 = $0.20
- EPA+DHA: 90 + 35 = 125 mg; dose ratio 125 ÷ 250 = 0.5
- Cost per dosed serving: $0.20 ÷ 0.5 = $0.40
Bottle B costs $21.00 for 60 servings. Each serving lists EPA 400 mg and DHA 200 mg.
- Price per serving: $21.00 ÷ 60 = $0.35
- EPA+DHA: 400 + 200 = 600 mg; 600 ÷ 250 = 2.4, capped at 1
- Cost per dosed serving: $0.35 ÷ 1 = $0.35
Per serving, Bottle A looks cheaper: $0.20 against $0.35. But one serving of A holds half the reference amount, so reaching 250 mg costs $0.40 with A and $0.35 with B. The order flips once the EPA and DHA rows are read.
Going past 250 mg earns nothing extra
Bottle B's serving holds 600 mg, 2.4 times the reference amount, and its ratio is still 1. A serving with exactly 250 mg at the same price would get the same cost per dosed serving. The number measures what it costs to reach the reference amount; it does not reward a bigger figure on the label.
If a label carries more than one ingredient the site recognises, such as fish oil with added vitamin D3, the dose ratio is the average across them, each capped at 1. If too little of a label can be checked against the reference, no cost per dosed serving is published.
Cost per dosed serving is ranked against every other product in the category to give the value score. See how fish oils compare in the health support rankings.