Question 1

Why does formulation matter so much?

Accepted Answer

Re-esterified triglyceride (rTG) delivers about 85% of the label dose; ethyl esters (EE) on a low-fat meal drop to roughly 30%. That is a 2–3x difference in actual physiological exposure for the same number on the bottle. Many 'negative' omega-3 trials used EE without controlling fat intake — the trial used the dose, but the patients did not absorb it. The calculator surfaces the absorbed mg alongside the label dose so you can compare products honestly.

Question 2

What is the AF (atrial fibrillation) risk and when does it apply?

Accepted Answer

REDUCE-IT (PMID 30415628) reported AF/flutter hospitalization at 3.1% on icosapent ethyl 4 g/day vs 2.1% on placebo — hazard ratio about 1.5. Real-world rates are 1/3 to 1/5 of trial rates, but the signal is real, especially in patients with prior AF history. The calculator caps the dose at 2 g/day for users reporting prior AF, regardless of goal. For users without AF history, doses at or above 4 g/day surface a non-blocking warning.

Question 3

Should I aim for the Omega-3 Index?

Accepted Answer

Yes if you can test it (RBC Omega-3 Index, several mail-in labs offer it). The optimal cardiovascular target is greater than 8%; the US average is 4–5%. Roughly 1 g/day EPA+DHA shifts the Index by about 1 percentage point over 3–4 months. The calculator does not require an Index input — it uses goal-based ranges that have shown clinical effect in trials — but the Index is the most useful biomarker if you want to verify you reached therapeutic exposure.

Question 4

Cochrane says no all-cause mortality benefit. Why supplement?

Accepted Answer

The 2020 Cochrane review (PMID 32114706, 86 RCTs, 162,796 participants) confirmed that omega-3 supplementation does not reduce all-cause mortality. The benefit is narrower: triglyceride reduction (high-certainty), coronary heart disease mortality and events (low-to-moderate certainty), and indication-specific outcomes (RA disease activity, preterm birth prevention, dry eye). The calculator only dispenses doses for indications where the evidence is real. It does not pretend to extend lifespan in healthy adults.

Question 5

Pregnancy: how much DHA and which form?

Accepted Answer

300–600 mg DHA/day throughout pregnancy and lactation per the Cochrane 2018 review (PMID 30480773), which showed reduced preterm birth (RR 0.89) and early preterm birth (RR 0.58) with omega-3 supplementation. Choose a DHA-dominant TG/rTG or algal formulation. Avoid cod liver oil — vitamin A teratogenicity. Avoid ethyl esters unless taken with substantial dietary fat — fetal development is the wrong place to under-deliver.

Question 6

Is fish oil safe with anticoagulants?

Accepted Answer

REDUCE-IT (4 g/day, n=8,179) and VITAL (1 g/day, n=25,871) showed no significant increase in major bleeding even on aspirin. The theoretical concern is real but clinically minor at supplemental doses. Standard-of-care still applies: pause 7 days before scheduled surgery, and INR monitoring if on warfarin. Triple antithrombotic therapy is a relative contraindication — discuss with cardiology before adding fish oil.