Omega-3 Index
A simple blood test that tells you how much EPA and DHA is in your red blood cells — and whether your fish oil is actually doing anything.
The Omega-3 Index measures the percentage of EPA and DHA in your red blood cell membranes. It's the most reliable way to know if you're getting enough omega-3s — because what matters isn't how much fish oil you take, but how much actually gets into your cells.
What is the Omega-3 Index?
The Omega-3 Index is the percentage of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in your red blood cell membranes. It reflects your omega-3 intake over the last 3–4 months — similar to how HbA1c reflects average blood sugar.
This makes it much more reliable than a one-time blood draw for omega-3. It doesn't fluctuate with your last meal. It tells you what's actually been incorporated into your cells.
Most Indians score between 3–5%, well below the optimal 8%. This is a significant and fixable gap.
What your number means
| Omega-3 Index | Risk zone |
|---|---|
| < 4% | High risk — significantly elevated cardiovascular and cognitive risk |
| 4–8% | Intermediate — room for improvement |
| 8–12% | Optimal — lowest risk of heart disease, best brain protection |
An Omega-3 Index of 8% or above is associated with a 30% lower risk of fatal heart attack compared to an index below 4%. It's one of the most actionable biomarkers you can improve through supplementation alone.
How to raise your Omega-3 Index
2–3 g of combined EPA + DHA daily — taken with a fat-containing meal for best absorption. Use fish oil, krill oil, or algal oil (vegetarian).
Most people see their index rise by 2–4 percentage points after 3–4 months of consistent dosing. Retest at 4 months to confirm you've reached 8%.
- Eat fatty fish — salmon, mackerel, sardines, hilsa 2–3 times per week provide meaningful EPA/DHA
- Take with fat — omega-3 absorption improves significantly when taken alongside dietary fat
- Choose triglyceride-form fish oil — better absorbed than ethyl ester form (check the label)
- Vegetarians: use algal oil — provides DHA and EPA directly from algae; flaxseed oil (ALA) converts poorly
- Be consistent — unlike some supplements, omega-3 needs daily dosing over months to build up in cells
Is your fish oil actually working?
eterni tracks your Omega-3 Index over time alongside inflammation markers — so you know if your supplement is doing its job.
Get early accessFrequently Asked Questions
What is a good Omega-3 Index?
8% or above is considered optimal and is associated with the lowest cardiovascular risk. Most people in India and the West score between 3–5%, which puts them in the high-risk zone. Anything below 4% is considered deficient.
How do I raise my Omega-3 Index?
Take a high-quality fish oil or algal oil supplement providing at least 2g combined EPA+DHA daily. Most people need 3–4 months of consistent supplementation to move their index by 2–4 percentage points. Eating fatty fish 2–3 times per week helps but is usually not enough alone to reach 8%.
Is the Omega-3 Index available in India?
Yes, but not widely. A few specialty labs offer it as a dried blood spot test. It's not part of standard lipid panels. You may need to specifically request it or use a home-test kit that ships to a partner lab. The cost is typically ₹2,000–4,000.
Can I get enough omega-3 from vegetarian sources?
Plant sources like flaxseed and walnuts provide ALA, which your body converts to EPA and DHA very inefficiently (under 5%). For meaningful Omega-3 Index improvement, vegetarians should use algal oil supplements, which provide DHA and EPA directly from algae — no fish required.
Why the Omega-3 Index matters
The Omega-3 Index was proposed by Dr. William Harris as a risk factor for coronary heart disease. A large body of research now supports it as an independent predictor of cardiovascular mortality — on par with or superior to traditional markers like LDL cholesterol.
Beyond heart health, higher omega-3 levels are associated with slower brain aging (equivalent to 1–2 years of preserved brain volume), lower inflammation (measured by hsCRP), and reduced risk of depression.
India-specific considerations
India has one of the lowest average Omega-3 Indexes globally, estimated around 3–4%. This is driven by low fish consumption in much of the population, high omega-6 intake from vegetable oils, and limited supplementation. Vegetarians and vegans are particularly affected, as plant-based ALA converts to EPA/DHA at very low rates (2–5%).
Hilsa (ilish), Indian mackerel, and sardines are good local fish sources of EPA/DHA. For those who don't eat fish, algal oil is the most effective alternative.
Connected supplements & biomarkers
- Omega-3 (EPA/DHA) — the supplement that directly raises this index
- hsCRP — inflammation marker that omega-3 helps reduce
- Triglycerides — high-dose EPA/DHA lowers triglycerides by 20–30%
- HDL cholesterol — omega-3 modestly raises HDL
Know what's working. Know what's not.
eterni connects your lab results, supplements, and retests — so you can see the trajectory, not just a snapshot.
Join the waitlist