Omega-3 Index Plus
Omega-3 Index Plus. Extended analysis of EPA and DHA in red blood cell membranes, reported as a percentage. Target >8%; below 4% is associated with elevated cardiovascular risk. Reflects dietary omega-3 intake over the previous 2-3 months.
What It Measures
The Omega-3 Index Plus is an extended version of the standard Omega-3 Index, measuring the percentage of EPA and DHA omega-3 fatty acids in the membranes of your red blood cells. As with the standard Index, because red blood cells live for around 120 days, the result reflects your average omega-3 intake over the previous two to three months, a much more stable picture than any one-day snapshot. Omega-3 fatty acids are essential building blocks your body cannot synthesise itself; you must obtain them from oily fish, algae, or supplementation. They are incorporated directly into your cell membranes, keeping them flexible, supporting healthy inflammatory responses, and helping the electrical signalling in your heart and brain.
The "Plus" version is reported when the test is bundled within a broader panel (such as our Longevity Gold or Ultimate profiles). Interpretation is identical to the standalone Omega-3 Index: an index above 8 per cent is generally considered cardioprotective, 4 per cent or below is associated with higher cardiovascular and inflammatory risk, and most UK adults sit in the 4–6 per cent range. The target range reflects consistent epidemiological evidence linking higher omega-3 membrane status to reduced rates of sudden cardiac events, better cognition, and lower systemic inflammation.
Like the standalone Index, your level is driven primarily by dietary omega-3 intake. Oily fish two or three times per week is typically sufficient to reach the cardioprotective range for most people. EPA and DHA supplements are a reliable alternative for those who dislike fish or cannot source it. Changes take two to three months to reflect fully in cell membrane composition, so persistence matters. Your GP or a registered dietitian can advise on the most suitable approach for you.
What Your Results Mean
See where your Omega-3 Index Plus sits
A blood test that includes Omega-3 Index Plus, analysed with AI and read against your wider results.

