How Much Omega-3, 6 and 9 Do I Need Daily? The UK Figures in mg

There is no official UK supplement dose for omega-3. The UK advice is food: at least two portions of fish a week, one of them oily, which SACN calculated supplies about 450 mg a day of the long-chain omega-3s EPA and DHA. The label yardsticks are 250 mg of EPA and DHA a day (EFSA's adequate intake and the heart-claim threshold), 250 mg of DHA for the brain and vision claims, and 2 g of the plant omega-3 ALA for its cholesterol claim. Above about 1 g a day of EPA and DHA the large trials show a rising risk of atrial fibrillation, so more is not better; EFSA found no safety concern for adults at supplemental intakes up to 5 g.^{1, 2, 3, 4, 14} Omega-6 and omega-9 need no supplement figure; ordinary diets cover both, and the "2:1:1 ratio" sometimes quoted online has no basis in the evidence.⁵

• Food: two portions of fish a week, one oily, about 450 mg EPA+DHA a day^{1, 2}
• Ceiling: the AF signal rises above 1 g a day; EFSA found no safety concern up to 5 g EPA+DHA^{3, 4, 14}
• Units: a 1,000 mg fish oil capsule holds about 300 mg EPA+DHA; a flaxseed 3-6-9 capsule holds ALA and no EPA or DHA

Sources checked on 29 October 2026.

How many mg of omega-3 per day?

Every figure below is EPA and DHA, or ALA, never milligrams of oil.

How much omega-3 in food should I consume per day?

Enough fish to meet the NHS advice: at least two 140 g portions a week, one of them oily.² SACN worked out that this pattern averages about 450 mg of EPA and DHA a day, a figure that describes the fish advice rather than setting a target.¹ For ALA, 25 g of walnuts or two tablespoons of ground flaxseed reach the 2 g cholesterol-claim amount, and a tablespoon of flaxseed oil (about 7 g) or 25 g of chia (about 4.5 g) pass it.¹⁵ What foods are high in omega-3, 6 and 9 lists amounts per portion.

How to read the EPA and DHA figure on a label

Find the line that gives EPA and DHA in milligrams; the big number on the front is usually the weight of oil:

• "1,000 mg fish oil": standard fish oil is about 18% EPA and 12% DHA, so one capsule carries about 300 mg of EPA and DHA, a little above the 250 mg heart-claim figure and well under 1 g.
• "500 mg algal oil": read the DHA line against the 250 mg DHA threshold.
• "1,000 mg omega 3-6-9": a flaxseed capsule's figure is ALA plus linoleic plus oleic acid, with no EPA or DHA, often with vitamin E, which contributes to the protection of cells from oxidative stress.³

Gummies follow the same rule: a two-gummy serving typically holds tens of milligrams of algal DHA, read against the 250 mg DHA threshold, and any added vitamins carry their own wording: vitamin D contributes to the maintenance of normal bones and teeth, and vitamins A and C contribute to the normal function of the immune system.³ Algae omega-3 vs fish oil has typical figures by source.

Is 1,000 mg of omega-3 too much?

No; "1,000 mg" on a fish oil pot is usually oil, about 300 mg of EPA and DHA, and a true 1,000 mg is roughly what the largest prevention trials used. VITAL gave 25,871 adults 840 mg a day for five years with no excess of bleeding, cancer or serious harm.⁶ Pooled across 40 trials at varied doses, EPA and DHA cut heart attacks by about 13% and coronary deaths by about 9%; the Cochrane review found no change in overall deaths or strokes.^{7, 8} The reason not to go higher is atrial fibrillation: across seven large trials the relative risk of new AF was 12% higher at 1 g or less and 49% higher above 1 g, from a low starting rate of a few per cent over five years.⁴ Triglycerides fall about 15%, in proportion to dose, but the 2 to 4 g range where that matters belongs under a doctor's care, and the 5 g figure is a safety limit, not a target.^{3, 8, 14}

How often should I take omega-3, 6 and 9?

Daily, with a meal, at the label dose. Red-cell omega-3 levels respond to average intake over three to five months, so a missed day changes nothing: in a five-month dose-ranging trial, the daily amount alone explained 68% of the rise in the omega-3 index.⁹ When to take omega-3, 6 and 9 has the absorption evidence; should omega-3 be taken daily covers the diet question.

How much mg of omega-3 and omega-6 do I need daily?

For omega-6, nothing from a supplement. Linoleic acid is essential, and EFSA's adequate intake is 4% of energy, about 9 g a day on a 2,000 kcal diet, which cooking oils, spreads, nuts and seeds supply.⁵ Higher linoleic acid intake tracks lower, not higher, heart disease risk in pooled cohort data, and raising it in randomised trials caused no harm.^{10, 11} EFSA sets separate intakes for each fatty acid and no ratio, and every health claim built on an omega-6 to omega-3 ratio was rejected as unsubstantiated.^{3, 5} The differences between omega-3, 6 and 9 has the ratio evidence.

What are the signs I might be taking too much omega-3?

At supplement doses the signs are digestive and mild: fishy burps, loose stools, nausea and a lingering taste. Above about 1 g a day the concern is a new irregular heartbeat, so palpitations on a high dose are a reason to see your GP.⁴ Easy bruising or nosebleeds in someone on warfarin, a DOAC or aspirin should be reported to the anticoagulant clinic, although the pooled surgical data show no increase in bleeding with fish oil.¹² The side effects of omega-3, 6 and 9 has the full list; the Wellgard omega-3 guide covers the outcomes.

What we don't know

No UK body has set a supplement dose for EPA and DHA: the figures above are label thresholds and trial doses.^{1, 3} Whether 250 mg to 1 g a day changes hard outcomes in people who already eat oily fish is untested: the supplement-dose trials were neutral on their primary outcomes.^{6, 8}

Frequently asked questions

How much omega 3-6-9 should I take a day?

The label's daily serving, usually one or two flaxseed-oil capsules; no official intake exists for a 3-6-9. A two-capsule serving typically supplies several hundred milligrams of ALA, read against the 2 g of ALA a day at which the register's cholesterol wording applies, the linoleic and oleic acid alongside need no supplement figure.^{3, 5} A 3-6-9 contains no EPA or DHA, so the marks above do not apply to it.

Are omega-6 and omega-9 already in my diet?

Yes, both. Linoleic acid comes from cooking oils, spreads, nuts and seeds above the 4% of energy adequate intake, and oleic acid, which the body also makes, from olive and rapeseed oil, avocados and nuts.⁵ A flaxseed 3-6-9 contains both because the oil does.

How much omega-3 per day for seniors?

The same figures. VITAL's 840 mg a day was taken by adults over 50 for five years without excess harm; 1.8 g a day in 70 to 82 year olds after a heart attack almost doubled new AF, counting brief episodes found on screening, so older adults have the strongest reason to stay at or below 1 g unless a cardiologist says otherwise.^{6, 13}

Sources

1. Scientific Advisory Committee on Nutrition. Advice on fish consumption: benefits and risks. gov.uk (PDF), published 1 December 2004.
2. NHS. Fish and shellfish. nhs.uk, page last reviewed 26 June 2026.
3. Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. gov.uk, page last updated 19 May 2026.
4. Gencer B, et al. Marine omega-3 supplementation and atrial fibrillation risk. Circulation, 2021. Meta-analysis, 7 trials, 81,210 people, 4.9 years; NIH-supported. PubMed 34612056.
5. EFSA. Scientific opinion on dietary reference values for fats. EFSA Journal, 2010. doi.org/10.2903/j.efsa.2010.1461.
6. Manson JE, et al. Marine n-3 fatty acids and prevention of cardiovascular disease and cancer. New England Journal of Medicine, 2019. Randomised trial, 25,871 adults, median 5.3 years; publicly funded (NIH). PubMed 30415637.
7. Bernasconi AA, et al. Omega-3 dosage and cardiovascular outcomes. Mayo Clinic Proceedings, 2021. Meta-analysis, 40 trials, 135,267 people; funding not stated on PubMed. PubMed 32951855.
8. Abdelhamid AS, et al. Omega-3 fatty acids for the prevention of cardiovascular disease. Cochrane Database of Systematic Reviews, 2020. Cochrane review, 86 trials, 162,796 people, 12 to 88 months; non-commercial funding. PubMed 32114706.
9. Flock MR, et al. Erythrocyte omega-3 response to fish oil. Journal of the American Heart Association, 2013. Randomised trial, 115 adults, about 5 months; government and non-commercial grants. PubMed 24252845.
10. Marklund M, et al. Biomarkers of dietary omega-6 fatty acids and cardiovascular disease. Circulation, 2019. Pooled analysis, 30 cohorts, 68,659 people; NIH-supported; two authors report food-industry funding. PubMed 30971107.
11. Hooper L, et al. Omega-6 fats for the prevention of cardiovascular disease. Cochrane Database of Systematic Reviews, 2018. Cochrane review, 19 trials, 6,461 people, 1 to 8 years; WHO-funded. PubMed 30488422.
12. Begtrup KM, et al. No impact of fish oil supplements on bleeding risk. Danish Medical Journal, 2017. Systematic review, 52 publications; funding not stated on PubMed. PubMed 28552094.
13. Myhre PL, et al. Omega-3 supplements and atrial fibrillation: OMEMI trial. Clinical Nutrition, 2023. Secondary analysis of a trial, 1,014 patients aged 70 to 82, 2 years; some authors report fees from drug makers. PubMed 37515843.
14. European Food Safety Authority. EFSA assesses safety of long-chain omega-3 fatty acids. efsa.europa.eu, published 27 July 2012.
15. Public Health England. Composition of foods integrated dataset (CoFID). gov.uk, page last updated 19 March 2021.

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This article is general information, not medical advice. If you take anticoagulant or antiplatelet medicines, have a heart rhythm condition or are pregnant, speak to your GP or anticoagulant clinic before adding an omega-3 supplement.