How much omega-3 do you actually need?
There is a wide gap between the dietary recommendations on a government webpage and what published evidence shows is needed to reach the optimal Omega-3 Index. Here is how to think about your own number.
The official guidelines vs the evidence
The Australian NHMRC and the Heart Foundation recommend approximately 500 mg/day of combined EPA+DHA for general adult cardiovascular health. That figure is sensible as a population-level minimum, but published research suggests it is well below the dose most people need to reach the 8–12% Omega-3 Index range associated with the strongest outcome data.
Walker et al. (2019) modelled the dose-response and found that reaching 8% typically requires roughly 1,000–2,000 mg/day — depending on starting status, body composition, supplement form, and absorption. For most Australians starting around 4–5%, the official recommendation is unlikely to be enough on its own.
A worked example
From Australian average to target
- Current Omega-3 Index
- 4.5%
- Target Index
- 8.0%
- Gap
- 3.5 percentage points
- Dose-response (Walker 2019)
- ≈0.27 pp per 100 mg/day
- Required: ≈1,300 mg/day total EPA+DHA from diet and supplement combined
Most people will hit some of this through fish intake — two oily-fish meals per week is worth roughly 900 mg/day averaged out — and close the remainder with a supplement.
Targets for different goals
| Goal | Index target | Typical daily intake |
|---|---|---|
| General health | ~8% | 1,000–1,500 mg/day |
| Cardiovascular prevention | 8–12% | 1,500–2,000 mg/day |
| Pregnancy | DHA ≥4.9% | 800–1,000 mg/day DHA, often combined with EPA |
| Triglyceride reduction (clinical) | per clinician | 2,000–4,000 mg/day (per REDUCE-IT) |
Why dose response varies between people
- Body weight — higher mass typically needs a higher absolute dose for the same Index shift.
- Gut absorption — take with a fatty meal; absorption can double versus an empty stomach.
- Supplement form — re-esterified triglyceride forms are absorbed more efficiently than ethyl esters.
- Baseline status — lower starting Index means a larger absolute percentage-point gain per dose.
- Genetics — FADS gene variants alter conversion and incorporation.
The retest principle
Harris and von Schacky (2004) established the underlying biology: red blood cells live about 120 days, so a stable dose takes 3–4 months to fully reflect in your Index. The practical loop is simple — adjust your dose, hold it, retest at 12–16 weeks, repeat.
Keep reading
Get your personalised dose
Shop the tests →References: Walker RE et al. Predicting the effects of supplemental EPA and DHA on the omega-3 index. Am J Clin Nutr. 2019. · Harris WS, von Schacky C. The Omega-3 Index. Prev Med. 2004. · Bhatt DL et al. REDUCE-IT trial. NEJM. 2019. · Stark KD et al. Prog Lipid Res. 2016.