How much omega-3 per day
For general health, food-based guidance clusters around a few hundred milligrams of EPA plus DHA a day, not several grams. The 4 gram icosapent ethyl dose in REDUCE-IT was a prescription regimen in a selected high-risk group, and a different high-dose product failed in the STRENGTH trial. Higher omega-3 intakes have also been tied to a higher chance of atrial fibrillation. Read the EPA and DHA lines on the label. The milligrams of fish oil are not the same number.
A fish-oil softgel that says 1,000 mg is usually the weight of the oil, not the weight of EPA plus DHA. Omega-3 (EPA/DHA) dosing starts with those two numbers added together.
Everyday intake versus a treatment dose
European dietary-reference work set an adequate intake of 250 mg of EPA plus DHA a day for healthy adults (EFSA Journal 2010). That is a diet target, not a treatment. A 2017 American Heart Association science advisory reviewed fish-oil supplements for preventing clinical cardiovascular disease (PMID 28289069). It is not a blank check for high-dose capsules in people who have never had heart disease.
The trials people mix up
REDUCE-IT tested 4 grams a day of icosapent ethyl, a purified EPA prescription product, in people with high triglycerides who were already on a statin (PMID 30415628). Cardiovascular events were lower in that selected group. STRENGTH tested a different high-dose omega-3 carboxylic acid against corn oil and did not show a benefit (PMID 33190147). Those two results do not average out to "take 4 grams of the grocery-store bottle."
A 2025 review of omega-3 and atrial fibrillation describes a higher rhythm risk as the dose goes up (PMID 39617283). Chest symptoms, a racing heart, or a known rhythm problem are reasons to talk to a clinician before a high dose. Blood-thinning drugs are another.
A practical label check
Add EPA and DHA. Something in the few-hundred-milligram range matches the general-health target. Jamieson Omega 3 Select, Health Canada NPN 80002596, lists fish oil 1,000 mg providing 300 mg EPA and 200 mg DHA. That is 500 mg of the two acids, and the NPN is a licence to sell in Canada, not a purity seal. Prescription-strength EPA is a different product and a different decision.
Names that were on a public certification list are in certified omega-3 products compared.
Sources
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific opinion on dietary reference values for fats. EFSA Journal. 2010;8(3):1461. EFSA Journal.
- Siscovick DS, et al. Omega-3 polyunsaturated fatty acid (fish oil) supplementation and the prevention of clinical cardiovascular disease. Circulation. 2017. PMID: 28289069.
- Bhatt DL, et al. Cardiovascular risk reduction with icosapent ethyl for hypertriglyceridemia. N Engl J Med. 2019. PMID: 30415628.
- Nicholls SJ, et al. Effect of high-dose omega-3 fatty acids vs corn oil on major adverse cardiovascular events. The STRENGTH randomized clinical trial. JAMA. 2020. PMID: 33190147.
- Omega-3 and risk of atrial fibrillation: vagally-mediated double-edged sword. Prog Cardiovasc Dis. 2025. PMID: 39617283.