Omega-3 Fish Oil: What Trials Show, Cost per EPA+DHA
Omega-3 fish oil from the big trials: VITAL, REDUCE-IT and STRENGTH results, the atrial fibrillation signal, and monthly cost at the dose VITAL used.
Researched from published studies and manufacturer specifications, checked .
We have not tested products ourselves. How we research
Quick verdict
Over-the-counter fish oil did not reduce major cardiovascular events in VITAL, and a high-dose carboxylic-acid product did not in STRENGTH. Only a prescription purified EPA product cut events in high-risk patients on statins (REDUCE-IT). Omega-3 raised atrial fibrillation risk in a meta-analysis. Ask your doctor.
Talk to your doctor first. This is general information, not medical advice. Supplements and devices can interact with medicines and health conditions. We quote study protocols for context and do not recommend doses.
The short answer: ordinary fish oil has not been shown to prevent heart attacks or strokes in the big trials. VITAL (about 1 g/day) found no reduction in major cardiovascular events, STRENGTH (a high-dose product) found none, and only REDUCE-IT, using prescription purified EPA in high-risk patients already on statins, found a reduction. A meta-analysis links omega-3 supplements to more atrial fibrillation, more so above 1 g/day. Talk to your doctor before taking it, especially with heart disease or blood thinners.
The four studies that matter
Grades follow the rubric; the overall grade for over-the-counter fish oil for preventing cardiovascular events is Weak (no benefit shown in VITAL, a null result in STRENGTH), and Moderate only for the prescription EPA product in one high-risk group.
| Study | Who and what | Result |
|---|---|---|
| VITAL | 25,871 adults, 1 g/day marine n-3 (the trial’s capsule held 840 mg EPA+DHA), median 5.3 years, NIH-funded | Major cardiovascular events HR 0.92 (CI 0.80 to 1.06); heart attack HR 0.72 (secondary); no excess bleeding |
| REDUCE-IT | 8,179 patients with high triglycerides on statins, 4 g/day prescription icosapent ethyl, median 4.9 years, funded by the drug’s maker (Amarin) | Primary endpoint 17.2% vs 22.0% (HR 0.75); more atrial fibrillation hospitalisation (3.1% vs 2.1%); serious bleeding 2.7% vs 2.1% |
| STRENGTH | 13,078 high-risk statin-treated patients, 4 g/day omega-3 carboxylic acids vs corn oil | HR 0.99; stopped early for low probability of benefit; more gastrointestinal events (24.7% vs 14.7%) |
| Meta-analysis of 7 RCTs | 81,210 patients | Atrial fibrillation HR 1.25; HR 1.49 above 1 g/day vs 1.12 at 1 g/day or less |
Reading across them: the benefit appears tied to a specific prescription product in a specific high-risk group, not to over-the-counter fish oil in general. Why REDUCE-IT differs from STRENGTH (dose, formulation, placebo oil) is debated; we do not claim to settle it.
What it costs at the VITAL dose
From our cost per study dose dataset: brand pages and storefront data, 28 to 29 Sept 2026, one-time prices in USD (subscription discounts ignored), before tax and shipping. The basis is the dose used in VITAL, 840 mg EPA+DHA a day, and it is the EPA+DHA on the label that counts, not the oil weight: “1,200 mg omega-3” on a bottle is not 1,200 mg of EPA and DHA.
| Product | Price | EPA+DHA per serving | Per gram EPA+DHA | Per month at 840 mg/day | Testing stated |
|---|---|---|---|---|---|
| Carlson Elite Omega-3 Gems, 60 softgels | $28.20 | 1,400 mg (2 softgels) | $0.67 | $16.92 | IFOS certified (stated on page) |
| Thorne Super EPA | $45.00 | 695 mg | $0.72 | $18.13 | NSF Certified for Sport (stated on page) |
| Carlson Super Omega-3 Gems, 100 softgels | $36.60 | 1,000 mg (2 softgels) | $0.73 | $18.45 | IFOS certified (stated on page) |
| Carlson Maximum Omega 2000, 60 softgels | $39.90 | 1,750 mg (2 softgels) | $0.76 | $19.15 | IFOS certified (stated on page) |
| Momentous Omega-3 | $39.99 | 1,600 mg | $0.83 | $20.99 | NSF Certified for Sport and IFOS (stated on page) |
| Transparent Labs Omega 3 | $39.99 | not read | not calculated | not calculated | own batch results (self-published) |
Cost per gram of EPA+DHA is the fair comparator, and the spread is narrow: $0.67 to $0.83, or about $4 a month between cheapest and dearest at this dose. Carlson’s larger bottles cost less per softgel, so the figures for other sizes differ. Certification is where the products differ more: IFOS publishes lot results for fish oil, and NSF Certified for Sport screens for banned substances (what each certification checks). That price buys a marker of exposure, not a proven benefit, and prices are a convenience sample of brands whose pages we could read. We did not verify the Nordic Naturals product linked from this page: Carlson, Nordic Naturals.
Before you buy
A blood test can show whether triglycerides are high, which is the group REDUCE-IT studied. See where omega-3 sits in the graded supplement ladder and the complete longevity stack, and the omega-3 evidence card.
Method note
Researched from PubMed abstract records (29 Sept 2026) and brand pages (28 Sept 2026; Momentous prices re-checked 29 Sept 2026, unchanged). Abstracts only; grades are our judgement using the published rubric. We did not test any product. General information, not medical advice: this page gives no personal dose.
Before buying, see the Omega-3 Index test: what it is and what it costs.
See also: Longevity supplements with null trials: an evidence ledger.
Common questions
Does fish oil prevent heart attacks?
In VITAL (25,871 adults, about 1 g/day of omega-3) it did not significantly reduce major cardiovascular events (HR 0.92), though heart attack was lower as a secondary result (HR 0.72). In STRENGTH (13,078 high-risk statin-treated patients, omega-3 carboxylic acids) there was no benefit (HR 0.99). In REDUCE-IT (8,179 patients, prescription icosapent ethyl) events fell (HR 0.75).
Does fish oil increase the risk of atrial fibrillation?
A 2021 meta-analysis of 7 trials (81,210 patients) found marine omega-3 supplements were associated with a higher risk of atrial fibrillation (HR 1.25), larger in trials testing more than 1 g/day (HR 1.49). REDUCE-IT also reported more atrial fibrillation hospitalisations on treatment (3.1% vs 2.1%).
Should I take fish oil if I take blood thinners?
Ask your prescriber first. REDUCE-IT reported serious bleeding in 2.7% of patients on icosapent ethyl vs 2.1% on placebo (P=0.06), and VITAL saw no excess bleeding at about 1 g/day. Anyone on anticoagulants or facing surgery should get medical advice.
Sources
- VITAL, marine n-3 fatty acids (NEJM 2019) checked 29 Sept 2026
- VITAL principal results (J Steroid Biochem Mol Biol 2020; states the 1 g Omacor capsule held 840 mg EPA + DHA: 460 mg EPA, 380 mg DHA) checked 29 Sept 2026
- REDUCE-IT, icosapent ethyl (NEJM 2019) checked 29 Sept 2026
- STRENGTH, high-dose omega-3 carboxylic acids in statin-treated patients (JAMA 2020) checked 29 Sept 2026
- Marine omega-3 and atrial fibrillation risk in cardiovascular RCTs, meta-analysis (Circulation 2021) checked 29 Sept 2026
- Carlson, Super Omega-3 Gems, Elite Omega-3 Gems and Maximum Omega 2000 (prices, EPA and DHA per serving, IFOS statement) checked 29 Sept 2026
- Longevity Intel cost per study dose dataset (prices checked 2026-09-28; Momentous re-checked 2026-09-29) checked 29 Sept 2026
Update log
- Independent audit against the PubMed abstracts and Carlson, Momentous storefront data: overall grade for over-the-counter fish oil changed from Moderate to Weak (three large null trials); source added for the 840 mg EPA + DHA in the VITAL capsule; funding noted; prices stated as one-time. Cost per gram of EPA + DHA recomputed for all five products, unchanged.
- Priced three Carlson products (IFOS certified per its pages) alongside Thorne and Momentous, with cost per gram of EPA+DHA; dataset updated.
- Price re-check: Momentous prices re-checked 29 Sept 2026, unchanged.
- Sourcing pass: replaced the unsourced dose targets, brand rankings and 'who should prioritise' lists with the four landmark trials and meta-analysis, and priced two brands at the VITAL dose.
Data and comparisons
- Omega-3 (EPA/DHA) evidence record
The best-evidenced longevity supplement
- Vitamin D3 evidence record
Deficiency is endemic (over 40% of Western adults) and associated with higher all-cause mortality
- Magnesium evidence record
Required for 300+ enzymatic reactions
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