EPA and DHA are two long-chain omega‑3 fatty acids. Their source, actual content and the context studied make the difference.
Distinguishing EPA, DHA and ALA
EPA means eicosapentaenoic acid; DHA means docosahexaenoic acid. Fish and certain microalgae supply these long-chain fatty acids. Flaxseed oil, chia and walnuts mainly supply alpha-linolenic acid (ALA). Conversion of ALA into EPA, and especially DHA, is limited: equal milligram amounts are not equivalent. [2]
Algal oil may contain DHA alone or both EPA and DHA; check the declaration. [2]
Reading the label
The front label often highlights oil weight. For the EPA/DHA figures in this profile, the relevant amount is the sum of those two fatty acids per daily serving. Total omega‑3 can include other fatty acids too.
Hypothetical example: a capsule contains 1,000 mg fish oil, including 180 mg EPA and 120 mg DHA. That supplies 300 mg EPA + DHA, not 1,000 mg. If the declared serving is two capsules, the combined amount is 600 mg. This explains the label; it does not recommend a capsule count.
Always compare the same quantities: mg EPA, mg DHA and serving size. For liquid oil, check how many millilitres the declaration refers to.
What question is the research answering?
Adequate nutrition, a change in a blood marker and preventing a heart attack are different outcomes. A favourable laboratory change does not by itself establish a clinical benefit. A result with a high-dose medicine cannot simply be transferred to an ordinary food supplement.
The human perspective combines reference values with cardiovascular-outcome research. The animal perspective considers canine feeding and osteoarthritis studies. Both belong in one ingredient profile, with distinct scopes.
EPA and DHA in humans
Everyday nutrition, particular life stages and medical treatment involve different considerations. A single omega‑3 number cannot answer all of them.
How much omega‑3 should be consumed?
EFSA guidance: daily intake from the whole diet
Situation
Reference value
Meaning
Healthy adults
250 mg combined EPA + DHA
Adequate Intake (AI), not an additional capsule dose [1]
Dietary reference, not instructions to give infants adult preparations [1]
When is a closer look worthwhile?
A practical overview starts with three details: usual food sources, the EPA and DHA amounts declared by every preparation, and their daily serving sizes. This is more informative than asking for a universal number of capsules.
Little or no fish: identify the direct EPA/DHA sources actually present in the diet. Algal oil can provide them, depending on composition. [2]
Pregnancy or lactation: the additional DHA reference is a separate question, not a reason to adopt a medical high-dose regimen. [1]
Diagnosed lipid disorders or cardiovascular disease: discuss nutritional intake separately from drug treatment with the treating clinician. The studies below are not self-treatment instructions.
Older age: diet, conditions and medicines matter. Age alone does not justify adopting the 4-g regimens used in clinical trials.
A reference intake is different from a health claim
Under further product conditions, EU claims about normal heart function use 250 mg EPA + DHA/day; those concerning brain function and vision use 250 mg DHA/day. These quantities are not interchangeable. [3]
Such claims concern normal functions and do not permit promises to treat disease. Swiss authorisations and conditions apply in Switzerland. Publishing or linking a study does not automatically authorise a health claim for a product. [13]
What did the major studies find?
These publications address different questions. Comparisons only make sense when participants, formulation, dose and the measured outcome are considered together.
Finding. Increasing long-chain omega‑3 had little or no effect on all-cause mortality and many cardiovascular outcomes; small benefits were possible for some coronary outcomes. Triglycerides were reduced.
Interpretation & limitations. Totals include different omega‑3 interventions, including ALA. The search ended in 2019 and does not fully cover later trials. A blood-marker change does not establish fewer clinical events.
Manson et al. 2019 · 25,871 participants · median 5.3 years
VITAL: primary prevention in older adults
Finding. A daily 1-g oil capsule containing 460 mg EPA and 380 mg DHA did not significantly reduce the primary combined outcome of heart attack, stroke and cardiovascular death compared with placebo.
Interpretation & limitations. Participants had no known cardiovascular disease at entry. Some secondary findings were favourable, but do not justify a general protection claim. Only one dose was tested.
Bhatt et al. 2019 · 8,179 patients taking statins · median 4.9 years
REDUCE-IT: benefit in a defined patient group
Finding. With 4 g/day icosapent ethyl, primary events (cardiovascular death, heart attack, stroke, revascularisation or hospitalisation for unstable angina) occurred in 17.2% versus 22.0% with placebo: an absolute difference of 4.8 percentage points.
Interpretation & limitations. Highly purified EPA medicine, elevated triglycerides and high risk; not transferable to ordinary fish oil. Hospitalisation for atrial fibrillation/flutter was more frequent (3.1% vs 2.1%). Funded by Amarin.
Nicholls et al. 2020 · 13,078 high-risk patients taking statins
STRENGTH: another high-dose formulation without benefit
Finding. A 4-g/day formulation containing EPA and DHA did not outperform corn oil: primary events 12.0% versus 12.2% (p = 0.84). The trial stopped early for futility.
Interpretation & limitations. Formulation and comparator differed from REDUCE-IT. These trials are not a direct comparison of EPA against DHA. Funded by AstraZeneca.
In January 2026, EFSA retained a safe intake level of 1 g/day for supplemental DHA alone. This covers supplemental or added DHA, including DHA-dominant sources with an EPA/DHA ratio below 0.3. A UL could not be established because suitable dose–response data were lacking. This safe intake level is neither a recommended dose nor a blanket value for all EPA/DHA mixtures. [8]
EMA identifies a dose-dependent atrial-fibrillation risk with omega‑3-acid ethyl ester medicines in patients with cardiovascular disease or risk factors, highest at 4 g/day. This cannot be directly extrapolated to usual amounts in foods. [9]
With rhythm disorders, anticoagulant medicines or planned high-dose use, have the combination assessed by a clinician. Do not replace or change prescribed medicines because of a knowledge article. Research doses belong to their particular trial protocols.
EPA and DHA in dogs
A complete diet differs from an individual complementary feed. Assessment needs to consider the particular animal's entire ration.
How much for a dog?
FEDIAF 2025 gives no general EPA/DHA minimum in its adult-maintenance dog table. For growth and reproduction it recommends a minimum 0.13 g EPA + DHA per 1,000 kcal metabolisable energy in complete food. This is a food concentration, not an additional daily dose or an osteoarthritis treatment dose. [10]
The human 250 mg reference cannot be adopted directly or simply scaled by body weight. Individual ration assessment needs weight, life stage, energy intake, main food and all additions. The veterinary practice should also know about conditions and medicines.
Calculation example, not a dose recommendation: food providing 0.5 g EPA + DHA per 1,000 kcal supplies 0.2 g, or 200 mg, when 400 kcal is consumed. Only after accounting for existing intake can additional oil be assessed.
What has been studied in osteoarthritis?
Barbeau-Grégoire et al. 2022 · 57 articles · 72 trials across 9 categories
A review with positive signals
Finding. The analysis found positive signals for omega‑3-enriched diets and omega‑3 preparations in osteoarthritis. Totals cover all categories, not omega‑3 alone.
Interpretation & limitations. Different diets, preparations and outcome measures. Authors disclose previous work for animal-health and pet-food companies. Findings cannot be transferred to every animal or oil.
Individual trial: primary comparisons not significant
Finding. Fish oil versus corn oil produced no statistically significant between-group difference in any of the four primary outcomes.
Interpretation & limitations. Improvement within the fish-oil group alone does not demonstrate superiority to placebo. 71 dogs completed the study. This illustrates why owner observations and controlled comparisons need different interpretation.
Record EPA and DHA across the entire ration. “Salmon oil” alone does not specify an amount.
Complete and complementary feeds have different purposes. Consider the composition and instructions of any dietetic food already being used.
Lameness or pain needs veterinary diagnosis and management. Oil does not replace examination or pain treatment.
Do not use canine trials to determine a cat's dose. Species, life stage and the application studied remain essential.
Sources & further reading
Editorial date: 18 October 2026. Selected reference values, safety assessments and clinical publications, including the 2026 EFSA DHA assessment and FEDIAF 2025. Not an exhaustive systematic literature review. Original sources and publication years are linked.
Swiss regulatory framework · Accessed 18 October 2026
General nutrition and research information. Reference values, safety assessments and research doses serve different purposes. Not individual medical or veterinary dosing advice, or evidence of efficacy for an OMNENT product.
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