Does Flaxseed Oil Contain Omega-3, 6 and 9? ALA, EPA and DHA Explained

Yes. Flaxseed oil, also sold as linseed oil, contains all three: it is typically 40 to 60% alpha-linolenic acid (ALA, the plant omega-3), with 12 to 17% linoleic acid (omega-6), 13 to 19% oleic acid (omega-9) and about 9% saturated fat. That makes it the richest common food source of ALA and the oil inside vegan omega 3-6-9 capsules.^{1, 15} What it does not contain is EPA or DHA, the long-chain omega-3s in oily fish and algal oil. The body converts roughly 5% of ALA into EPA and under 1% into DHA, so flaxseed oil raises blood EPA a little and DHA not at all.^{2, 3, 4} The register's authorised claim for ALA, "contributes to the maintenance of normal blood cholesterol levels", applies at 2 g of ALA a day, which a tablespoon of flaxseed oil or two tablespoons of ground seed reaches.⁵

• Composition: about 40 to 60% ALA (typically 53%), 12 to 17% linoleic acid, 13 to 19% oleic acid
• Per tablespoon (about 14 g): roughly 7.5 g ALA; per teaspoon roughly 2.5 g
• Conversion: about 5% of ALA to EPA, under 1% to DHA; young women converted more in one tracer study
• Claim threshold: 2 g ALA a day for the cholesterol wording
• Seed or oil: ground seed adds fibre and lignans; oil is concentrated ALA

Sources checked on 29 October 2026.

What is flaxseed oil?

Flaxseed oil is pressed from the seeds of the flax plant, the one that gives linen its fibre. "Linseed" is the older British name for the same seed. Food-grade oil is cold-pressed and sold in dark bottles or capsules; the boiled linseed oil in a hardware shop is for wood, not food.

Is flaxseed oil omega-3 or omega-6?

Mostly omega-3. Around half or more of a typical flaxseed oil is ALA, the omega-3; about a seventh is linoleic acid, the omega-6; and about a sixth is oleic acid, the omega-9.^{1, 15} Those proportions give a tablespoon (about 14 g) roughly 7.5 g of ALA, 2 g of linoleic acid and 2.5 g of oleic acid, a teaspoon roughly 2.5 g of ALA, and a 1,000 mg capsule roughly 500 to 550 mg. Two 1,000 mg capsules therefore supply roughly half of the 2 g of ALA a day at which the authorised cholesterol claim applies.⁵

Does flaxseed oil give you EPA and DHA?

Only a little EPA, and in effect no DHA. ALA is the starting point of the pathway that makes EPA and then DHA, but most ALA is burnt for energy instead. In tracer studies, young women converted an estimated 21% of a labelled ALA dose to EPA and 9% to DHA, young men some to EPA and none to DHA, and the broad reading across studies is about 5% to EPA and under 1% to DHA.^{2, 3, 4, 6} A twelve-week trial in 62 firefighters giving 2.4 to 3.6 g of flaxseed oil a day raised red-cell EPA; fish oil raised DHA quickly and flaxseed oil did not.⁷ The Wellgard omega-3 guide sets the three out side by side and How to get enough omega-3 on a vegan diet covers the algal route.

What is flaxseed oil good for?

ALA is an essential fatty acid: the body cannot make it and uses it for cell membranes and as the raw material for EPA.⁶ Across 41 cohorts and 1.2 million people, those eating the most ALA had 10% lower all-cause and 8% lower cardiovascular mortality than those eating the least, with 6% higher cancer mortality, and an earlier pooled analysis of 27 studies found 14% lower cardiovascular risk; these are associations with ALA from food, not trials of capsules.^{8, 9} In the randomised trials pooled by Cochrane, ALA made little or no difference to deaths or heart events, with a possible reduction in heart rhythm disturbances.¹⁰ The authorised claim is narrower than either: ALA "contributes to the maintenance of normal blood cholesterol levels" at 2 g a day, and the 28 pooled lipid trials found significant falls in total and LDL cholesterol with whole flaxseed and with lignan extracts but not with the oil alone.^{5, 11} Across 14 trials flaxseed lowered blood pressure by about 2 mmHg, most clearly as whole seed over twelve weeks or more.¹²

Ground flaxseed or flaxseed oil?

They are different foods. The seed carries the ALA inside fibre (about 28% of its weight), protein and lignans, the plant compounds behind the cholesterol and blood-pressure results above.^{1, 11, 12} ALA is absorbed better from oil or milled seed than from whole seed, so grind seeds or buy them milled.¹ The oil is the concentrated ALA with the fibre and most of the lignans left behind, which is what makes it the capsule ingredient.

How should you store flaxseed oil?

In the fridge, in its dark bottle, used within a few weeks of opening and never heated: with three double bonds, ALA oxidises far faster than the oleic and linoleic acids of cooking oils, flaxseed oil oxidises easily once pressed, and oxidised oil tastes bitter and paint-like.¹ A survey of 171 North American omega-3 supplements found about half over the voluntary oxidation limits, with plant oils no worse than fish oils and encapsulated oils faring better than bottled ones, the case for capsules if a bottle would last you months.¹³

Who should not take flaxseed oil?

Anyone on warfarin or another anticoagulant should tell their GP or anticoagulant clinic what they take and keep the dose constant; the pooled surgical data on fish oil found no increase in bleeding, and flaxseed oil has not been studied for it.¹⁴ In pregnancy there are no safety trials at supplement doses, so follow the label and ask your midwife. The lignans in flaxseed have weak oestrogen-like activity,¹ which has raised a question about hormone-sensitive conditions; the oil contains little lignan, the human evidence has not shown harm, and anyone with such a condition should ask their specialist.

What we don't know

Whether flaxseed oil on its own, as distinct from whole seed, changes cholesterol: the oil-only trials did not reach significance.¹¹ Whether a higher ALA intake lowers mortality or marks a diet that does: the Cochrane ALA trials found little or no difference to deaths.^{8, 10} Why young women converted far more ALA to DHA than men in tracer studies, and whether that holds outside the laboratory.^{2, 6}

Frequently asked questions

Is flaxseed a vegan alternative to omega 3-6-9?

Flaxseed oil is what a vegan omega 3-6-9 capsule is made of, with ALA as the omega-3; check that the capsule shell is plant cellulose rather than gelatine. Is it better to take omega-3 or omega 3-6-9 compares the two.

What plant has all four omegas?

None. Plants make ALA (omega-3), linoleic acid (omega-6) and oleic acid (omega-9); walnuts, hemp and flaxseed carry all three. EPA and DHA come from marine algae and the fish that eat them, so the only plant-based source of those is algal oil; fish oil contains EPA and DHA and almost no ALA, and the three omega-3s are not interchangeable.⁴

Is ALA enough for omega-3?

For the essential fatty acid itself, yes, and 2 g a day is easy to reach from food. For DHA, barely: young women convert a little in tracer studies, but flaxseed oil did not raise blood DHA in a twelve-week trial, so DHA comes from an algal source.^{2, 3, 7}

How much flaxseed oil per day?

No upper limit is set. The claim threshold is 2 g of ALA, under a tablespoon of oil; the trial that raised blood EPA used 2.4 to 3.6 g of oil a day for twelve weeks.^{5, 7} Flaxseed and an algal or fish oil can be taken together; no interaction is documented. How much omega 3-6-9 do I need daily gives the reference amounts for each.

Can you take flaxseed oil as capsules?

Yes. A 1,000 mg flaxseed-oil capsule supplies roughly 500 to 550 mg of ALA, so a tablespoon of the oil equals about fourteen capsules.¹⁵ When to take omega 3-6-9 covers timing.

Sources

1. Goyal A, et al. Flax and flaxseed oil: an ancient medicine and modern functional food. Journal of Food Science and Technology, 2014. Review; funding not stated on PubMed. PubMed 25190822.
2. Burdge GC, Wootton SA. Conversion of alpha-linolenic acid to EPA, DPA and DHA in young women. British Journal of Nutrition, 2002. Tracer study, young women, 21 days; funding not stated on PubMed. PubMed 12323090.
3. Plourde M, Cunnane SC. Extremely limited synthesis of long chain polyunsaturates in adults. Applied Physiology, Nutrition, and Metabolism, 2007. Review; funding not stated on PubMed. PubMed 17622276.
4. Lane K, et al. Bioavailability and potential uses of vegetarian sources of omega-3 fatty acids. Critical Reviews in Food Science and Nutrition, 2014. Systematic review, 10 intervention studies; funding not stated on PubMed. PubMed 24261532.
5. Great Britain nutrition and health claims (NHC) register. Page last updated 19 May 2026. gov.uk.
6. Burdge GC, Jones AE, Wootton SA. EPA and DPA are the principal products of alpha-linolenic acid metabolism in young men. British Journal of Nutrition, 2002. Tracer study, 6 men, 21 days; funding not stated on PubMed. PubMed 12323085.
7. Barceló-Coblijn G, et al. Flaxseed oil and fish-oil capsules and red blood cell n-3 fatty acids. American Journal of Clinical Nutrition, 2008. Randomised trial, 62 firefighters, 12 weeks; publicly funded (NIH). PubMed 18779299.
8. Naghshi S, et al. Alpha linolenic acid and risk of all cause, cardiovascular and cancer mortality. BMJ, 2021. Meta-analysis, 41 cohorts, 1,197,564 people; university-funded. PubMed 34645650.
9. Pan A, et al. Alpha-linolenic acid and risk of cardiovascular disease. American Journal of Clinical Nutrition, 2012. Meta-analysis, 27 studies, 251,049 people; publicly funded (NIH). PubMed 23076616.
10. Abdelhamid AS, et al. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews, 2020. Cochrane review, 86 trials, 162,796 people; no conflicts declared. PubMed 32114706.
11. Pan A, et al. Meta-analysis of the effects of flaxseed interventions on blood lipids. American Journal of Clinical Nutrition, 2009. Meta-analysis, 28 randomised trials; funding not stated on PubMed. PubMed 19515737.
12. Khalesi S, Irwin C, Schubert M. Flaxseed consumption may reduce blood pressure. Journal of Nutrition, 2015. Meta-analysis, 14 controlled trials; funding not stated on PubMed. PubMed 25740909.
13. Jackowski SA, et al. Oxidation levels of North American over-the-counter n-3 supplements. Journal of Nutritional Science, 2015. Laboratory survey, 171 products; funding not stated on PubMed. PubMed 26688721.
14. Begtrup KM, Krag AE, Hvas AM. No impact of fish oil supplements on bleeding risk: a systematic review. Danish Medical Journal, 2017. Systematic review, 52 publications; funding not stated on PubMed. PubMed 28552094.
15. Public Health England. Composition of foods integrated dataset (CoFID), 2021 (no flaxseed oil profile). Page last updated 19 March 2021. gov.uk. Flaxseed oil: USDA FoodData Central, SR Legacy, Oil, flaxseed, cold pressed. fdc.nal.usda.gov.

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This article is general information, not medical advice. If you are pregnant, take an anticoagulant or have a hormone-sensitive condition, ask your GP, midwife or specialist before adding flaxseed oil.