How much omega 3 should you take a day?

EFSA sets the adequate intake for an adult at 250 mg a day of EPA and DHA combined. Careful reading the label: it is the sum of those two, not the milligrams of fish oil in the pack. A 1000 mg per capsule tub rarely provides more than 300 mg of EPA+DHA.

What is the difference between EPA and DHA?

They are the two long-chain omega 3 fatty acids that fish provides. DHA is structural and abundant in the brain and retina; EPA is more associated with inflammatory signalling. General recommendations refer to the sum of both, which is why this site compares that way.

Why does certification matter so much for omega 3?

Because fish oil oxidises with heat, light and time, and because it can carry contaminants from the fish. An analysis of 32 products found only 3 reached the EPA+DHA on their label and most exceeded oxidation limits. A certification that tests the batch in an independent lab is the difference here between buying a fact and buying a promise.

Is omega 3-6-9 any good?

For supplying EPA and DHA, no. Omega 6 is already in excess in the Western diet and only dilutes what you are after. This site excludes 3-6-9 products from the category for that reason.

Can I take omega 3 if I am vegan?

Yes, with microalgae oil, which is the original source fish get their EPA and DHA from. It mostly provides DHA and is usually more expensive per milligram, but it is the only direct route without fish. Omega 3 from flax or chia is a different type (ALA) and the body converts it very poorly.

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Omega 3 · Strong evidence

What omega 3 is for and how much to take a day

The short answer. With omega 3, what you are buying is EPA+DHA, not the milligrams of fish oil printed large on the tub. The adequate intake for an adult is 250 mg a day of the two combined, and a 1000 mg oil capsule rarely exceeds 300 mg of EPA+DHA. It is also the category where quality certification matters more than any other: fish oil oxidises, and when someone went to check, most of the tubs analysed did not comply.

Several meta-analyses or position stands from scientific societies agree that there is an effect. No figure on this page is attributed to a specific product: the effect belongs to the ingredient and every number carries its source next to it.

01 What it does and how much

Each row is a measured effect, with the figure the study gives and the source number. Where the evidence gives no figure, the column says so instead of making up a percentage.

Effects of omega 3 with their source
Effect	How much	Detail
Adequate intake of EPA+DHA	250 mg/day	It is EFSA’s reference figure for an adult, and it refers to EPA and DHA COMBINED, not the oil on the pack. This is the number to read any label with. [1]
Blood triglycerides	-20 to -30 %	With doses of 2 to 4 g a day of EPA+DHA, which are treatment doses, not maintenance doses. At that level it is a medical decision with follow-up, not a gym purchase. [2]
Actual content versus the label	3 of 32	In an analysis of 32 fish oils on the market, only 3 contained the EPA+DHA they declared, and most exceeded the recommended oxidation limits. That is why in this category a batch-testing certification is worth far more than a low price. [3]

02 How to take it

Dose. 250 mg a day of EPA+DHA combined as a general reference. Uses at 2-3 g are something else and have a doctor behind them.
When. With a meal that contains fat: it improves absorption and reduces fishy reflux.
How long before you notice it. Months to change membrane composition. It is not a supplement you notice in one session.

Details that change the result

Read the label looking for EPA and DHA per capsule, not "fish oil 1000 mg". It is the most expensive confusion in this category.
If the tub smells or tastes strongly of rancid fish, it is oxidised. An oxidised omega 3 does not just lose its effect: it is not something you want to take.
Keep it in the fridge and do not buy giant packs that will stay open for a year.
Vegan: there is omega 3 from microalgae, which is where fish get it from. It mostly provides DHA.
With anticoagulants or before surgery, ask first: at high doses it can lengthen bleeding time.

03 When it makes sense and when it does not

Worth it if

You eat oily fish less than twice a week, which is the most common case.
Vegan or vegetarian diet: EPA and DHA intake is practically zero and algae are the route.
Pregnancy and breastfeeding, for DHA, but following the doctor’s advice.

Not worth it if

You already eat oily fish two or three times a week: sardines, mackerel, salmon or anchovies cover the reference easily and cost less.
Looking for an effect on performance or muscle mass: that is not what it does.
Buying on price per capsule without looking at EPA+DHA. A cheap capsule with 100 mg is not cheap, it is half a dose.

04 Sources

Every figure above comes from here. They are position stands from scientific societies, meta-analyses and peer-reviewed reviews: if a claim cannot hang from one of these lines, it is not on the page. References are cited in their original form.

EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on Dietary Reference Values for fats. EFSA Journal. 2010;8(3):1461. Ingesta adecuada de 250 mg diarios de EPA+DHA. doi:10.2903/j.efsa.2010.1461
Skulas-Ray AC et al. Omega-3 fatty acids for the management of hypertriglyceridemia: a science advisory from the American Heart Association. Circulation. 2019;140(12):e673-e691. doi:10.1161/CIR.0000000000000709
Albert BB et al. Fish oil supplements in New Zealand are highly oxidised and do not meet label content of n-3 PUFA. Sci Rep. 2015;5:7928. doi:10.1038/srep07928

This is not medical advice. It is what some studies say about an ingredient, not a protocol for you. With an illness, medication or pregnancy involved, the decision belongs to a healthcare professional who knows you.

Questions about omega 3

Answered with the data on this page

How much omega 3 should you take a day?: EFSA sets the adequate intake for an adult at 250 mg a day of EPA and DHA combined. Careful reading the label: it is the sum of those two, not the milligrams of fish oil in the pack. A 1000 mg per capsule tub rarely provides more than 300 mg of EPA+DHA.
What is the difference between EPA and DHA?: They are the two long-chain omega 3 fatty acids that fish provides. DHA is structural and abundant in the brain and retina; EPA is more associated with inflammatory signalling. General recommendations refer to the sum of both, which is why this site compares that way.
Why does certification matter so much for omega 3?: Because fish oil oxidises with heat, light and time, and because it can carry contaminants from the fish. An analysis of 32 products found only 3 reached the EPA+DHA on their label and most exceeded oxidation limits. A certification that tests the batch in an independent lab is the difference here between buying a fact and buying a promise.
Is omega 3-6-9 any good?: For supplying EPA and DHA, no. Omega 6 is already in excess in the Western diet and only dilutes what you are after. This site excludes 3-6-9 products from the category for that reason.
Can I take omega 3 if I am vegan?: Yes, with microalgae oil, which is the original source fish get their EPA and DHA from. It mostly provides DHA and is usually more expensive per milligram, but it is the only direct route without fish. Omega 3 from flax or chia is a different type (ALA) and the body converts it very poorly.

And now, which to buy

Prices, kept apart from the evidence

This page explains what omega 3 does and deliberately names no brand. The comparison is the other half: 152 products from 14 stores from €0.041 per capsule, sorted by price and by how verifiable their certification is.

See the omega 3 comparison

Other guides

What each supplement does, with its sources