Omega-6 to omega-3 ratio optimal range and reference range

Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026

Sera's bands for Omega-6 to omega-3 ratio:

Optimal 2 – 4 ratio; sufficient 2 – 6 ratio; out of range above 6 ratio.

Evidence grade: Functional / longevity target. A narrower target in common use in functional, integrative, preventive and longevity practice. It is not a universally validated diagnostic range.

All units

Unit	Optimal	Sufficient	Out of range
ratio	2 – 4	2 – 6	above 6

Bounded on the high side only — a low result is not treated as out of range. No source gives a lower limit and a low ratio only reflects high omega-3 status.

What the evidence says

Functional-medicine consensus supports a total omega-6 to omega-3 ratio around 2 to 4:1, against the 10 to 20:1 or higher typical of Western diets; those figures describe diet, and no published source sets them for red cells. The mechanism is well described: the two families compete for the same desaturase and elongase enzymes. In UK Biobank a higher plasma ratio went with higher mortality, but no threshold came out of it. Worked from published cohort averages, this red cell ratio sits at about 3.5 to 4.3 in North American and southern European groups whose Omega-3 Index is low, so an Optimal result here does not mean omega-3 status is adequate: read the Omega-3 Index first. This is the dietary-pattern version of the balance; AA:EPA is the eicosanoid version and the two are not interchangeable. Sera sums only the fatty acids present on the panel, so the number is comparable across draws only when the same panel was run.

Sources

Higher ratio of plasma omega-6/omega-3 fatty acids is associated with greater risk of all-cause, cancer, and cardiovascular mortality: A population-based cohort study in UK Biobank — Zhang Y, Sun Y, Yu Q, et al. — eLife, 2024 · Peer-reviewed publicationUK Biobank, 85,425 people: the highest fifth of plasma omega-6 to omega-3 ratio had 26% higher total mortality and 31% higher cardiovascular mortality than the lowest fifth. Supports the direction only; measured in plasma by NMR, not in red cells, and gives no threshold.
Red Blood Cell Fatty Acid Patterns from 7 countries: Focus on the Omega-3 Index — Schuchardt JP, Cerrato M, Ceseri M, et al. — Prostaglandins, Leukotrienes and Essential Fatty Acids, 2022 · Peer-reviewed publicationPublished red cell cohort means from which Sera's formula can be worked out: about 3.5 to 4.3 in United States, Canadian, Italian and Spanish cohorts and about 2.1 to 2.7 in Japan, Korea and Alaska. The paper does not report the ratio itself.
The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases — Simopoulos AP — Experimental Biology and Medicine, 2008 · Peer-reviewed publicationArgues that the two families compete for the same desaturase and elongase enzymes, so the balance between them matters and not the absolute intake of either. Sets out the low single-figure ratio widely used as a functional target against the 15:1 or higher typical of Western diets. The mechanism is well described; the specific target figure is consensus rather than an outcome-validated threshold.

What Total Omega-6:Omega-3 Ratio measures

Every omega-6 fatty acid measured, divided by every omega-3 fatty acid measured.

Calculated: (LA + AA + DGLA + GLA) / (EPA + DHA + ALA + DPA)

Related fatty acids markers

See Omega-6 to omega-3 ratio in the full list of biomarker ranges

This page is a reference for practitioners, not medical advice. Sera's bands are practitioner targets for structured review, not diagnostic thresholds, and Sera does not diagnose or recommend treatment. Read a result alongside the interval printed by the issuing laboratory and the client's history and symptoms. Range set: Sera Production, version 1.0, last reviewed November 9, 2026.