Check a label

Ingredient

EPA + DHA

Research dose

1000–6000 mg/day

Moderate EPA + DHA works through daily use over weeks: it builds up in the body. A lower daily amount still builds up, just more slowly.

The ISSN's 2026 position stand: 1000–6000 mg of EPA and DHA together a day for 6–12 weeks, with moderate evidence for performance and recovery. Only EPA and DHA count: a label's fish-oil weight and its other omega-3s are not what studies dose. The IOC's 2018 consensus puts the dose at about 2 g a day and says it is unclear whether athletes gain more than from eating fatty fish.

Sources

  1. Gonzalez DE, Dickerson BL, Roberts BM, et al. International Society of Sports Nutrition position stand: effects of dietary antioxidants on exercise and sports performance. J Int Soc Sports Nutr. 2026;23(1):2629828.

    Supports the research dose. Where: Position point 10: "omega-3 fatty acids (1000–6000 mg/day EPA+DHA for 6–12 weeks) ... with moderate- to high-quality evidence supporting their use in recovery or performance"; Table 2, Omega-3 fatty acids: "1000–6000 mg/day EPA + DHA for 6–12 weeks", performance evidence "Moderate". Read the source, checked 9 Oct 2026.

  2. Maughan RJ, Burke LM, Dvorak J, et al. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med. 2018;52:439-455.

    Supports the research dose. Where: Table 5 (supplements that may assist with training capacity, recovery, muscle soreness and injury management), Omega-3 fatty acids: "About 2 g/day"; "Low risk but unclear if supplementation should be pursued by athletes, in lieu of including fatty fish in the diet". Read the source, checked 9 Oct 2026.

Omega-3 supplements we've checked

21 omega-3 supplements, each judged on how much a day its label's own directions give. See them all, ranked.

What it takes to raise your omega-3 index

The omega-3 index is the share of EPA and DHA in your red blood cells, measured with a blood test; it reflects your intake over the past few months. A pooled analysis of 14 trials (1,422 people) found that about 2 g of EPA and DHA a day, taken for about 14 weeks, raised it from 4.9% to 8.1% on average. At 850 mg a day of an ethyl-ester oil it predicted about 6.5%. Gram for gram, triglyceride oils raised it about 1 percentage point more than ethyl esters (Walker et al., 2019).

How fast depends on the dose: in college football players given DHA, 6 g a day took the index past 8% in about 8 weeks and 4 g a day in about 15 (Lust et al., 2023). That is one reason we judge a product on its EPA and DHA a day, not on the fish-oil weight on the front: Nature Made's "Fish Oil 1000 mg" softgel gives 250 mg of EPA and DHA.

Research context, not advice. If you take blood thinners, ask a doctor before taking fish oil in high doses.