Best fish oil supplements: NSF-certified picks by EPA and DHA

We ranked by third-party testing, then form, then dose.

Third-party testing. Every product appears on NSF's certified supplement listing (NSF/ANSI Standard 173), checked November 3, 2026.

Form. NIH's omega-3 fact sheet says omega-3s as re-esterified triglycerides, natural triglycerides and free fatty acids have somewhat higher bioavailability than ethyl esters, though every form significantly raises blood levels. So a product whose label record states a triglyceride form ranks ahead of one whose record does not say. "Not stated" means the NIH record is silent; the bottle may say more.

Dose. EPA plus DHA per serving, measured against the 840 mg a day (460 mg EPA, 380 mg DHA) used in VITAL, the largest primary-prevention trial in adults over 50. A serving that reaches it ranks ahead of one that does not, and all stay well under the 5 g a day of EPA plus DHA that FDA has concluded is safe in supplements. Products tied within a tier are listed alphabetically.

A product also needed a current NIH label record matching its NSF row.

No product on this page pays us, and none of the product links below is an affiliate link. Each row links to two public records instead: the product's row on NSF's certified supplement listing, and its label in the National Institutes of Health (NIH) Dietary Supplement Label Database. How to read both yourself is in how to check whether a supplement is third-party tested.

Certified, but we could not read a current label. Thorne Super EPA is on NSF's listing, but every label for it in the NIH database is marked off the market. Nordic Naturals' NSF rows are for its Sport versions; the NIH database holds the non-Sport Ultimate Omega 2X but no matching 2X Sport record, so only the Omega-D3 Sport is ranked.

Two record notes. Momentous has two NIH records for Omega-3; we used the newer one (June 2025). The older one enters the amounts as "750 Gram(s)", an obvious unit error. And Nordic's Omega-D3 Sport adds 1,000 IU of vitamin D, which counts toward your daily vitamin D total.

USP Verified: not checked. USP runs a separate verification program. Its public lookup refused our automated requests on November 3, 2026, so we did not check any product against it. "Not checked" in the table means we did not look. It does not mean a product failed.

NIH says a typical fish oil supplement provides about 1,000 mg of fish oil containing 180 mg of EPA and 120 mg of DHA, and that doses vary widely. A bottle that says "1,000 mg" on the front may give you 300 mg of the omega-3s that matter. Every dose in our table is EPA plus DHA from the label record.

Algal oil is the vegetarian option. NIH says algal supplements usually provide 100 to 300 mg of DHA, some with EPA, and that one small study found DHA from algal oil as bioavailable as DHA from cooked salmon. On mercury, NIH says omega-3 supplements have not been found to contain it, because it is removed during processing.

VITAL. 25,871 adults (men 50 and older, women 55 and older) took 840 mg of EPA plus DHA or placebo for a median 5.3 years. Major cardiovascular events combined did not fall. Total heart attacks did fall 28%, with larger reductions among African American participants (77%) and people who ate less than 1.5 servings of fish a week (40%), per NIH's summary. Those are subgroup findings, which need confirming.

Cochrane, 2020. Across 86 trials and 162,796 people, long-chain omega-3s lowered triglycerides by about 15% and slightly reduced cardiovascular deaths and coronary events, with no effect on all-cause mortality, stroke or arrhythmia.

REDUCE-IT is not about supplements. Its benefit came from 4 g a day of icosapent ethyl, a prescription drug, in people already on statins with high triglycerides. A similar 4 g trial of a different prescription omega-3, STRENGTH, found no benefit, and NIH notes the mineral-oil placebo in REDUCE-IT may explain part of the gap. If your triglycerides are high, that is a prescription conversation; our triglycerides guide explains the numbers.

Side effects are usually mild, per NIH: unpleasant taste, bad breath, heartburn, nausea, diarrhea and headache. Two large trials found that 4 g a day for several years slightly raised the risk of atrial fibrillation in people with or at high risk of heart disease. Fish oil can have antiplatelet effects at high doses and might raise INR in people on warfarin, though NIH says most research finds 3 to 6 g a day does not significantly change anticoagulation. If you take a blood thinner, ask before starting.