Omega-3 index: what 449 blood tests reveal

Most people have never measured their omega-3 level, so they have no real idea whether they get enough. To see where people actually stand, we analysed 449 omega-3 blood tests from our own test results. Nearly four out of five results came back below the level that researchers link to lower long-term risk. These are measured results from dried blood spots, not a survey or an estimate, with every sample broken down fatty acid by fatty acid. This article walks through what the data shows across three markers, the omega-3 index, the omega-6 to omega-3 ratio, and the AA:EPA ratio, and what each one means for your own omega-3 status.

What you will learn in this article

1. What is the omega-3 index, and what is a healthy level?
2. What 449 blood tests revealed
3. Why the omega-6 to omega-3 ratio matters
4. What the AA:EPA ratio says about inflammatory balance
5. What AA:EPA you can expect at a given index
6. Why you can't dose omega-3 from a label
7. Does flaxseed raise your omega-3 index?
8. How long does it take to raise your omega-3 index, and when to retest?
9. How to raise a low omega-3 index
10. Key takeaways

What is the omega-3 index, and what is a healthy level?

The omega-3 index is the amount of EPA and DHA, the two long-chain marine omega-3 fatty acids, measured in the membranes of your red blood cells and expressed as a percentage of all the fatty acids there. It is a status marker, not a snapshot. It reflects how you have eaten over the previous weeks and months, not what was on your plate yesterday. A single meal cannot move it, and a single meal cannot hide it, which is what makes it worth measuring.

Research groups led by Clemens von Schacky put the healthy range at 8 to 11 percent. In work indexed on PubMed, a low omega-3 index meets the criteria for a cardiovascular risk factor, and higher blood levels of EPA and DHA are consistently associated with lower risk in population studies.^[1][2] A result below 4 percent sits at the high-risk end. In practice the index sorts people into three bands: under 4 percent, 4 to 8 percent, and 8 percent or above.

What 449 blood tests revealed

Here is where the 449 results landed. The median omega-3 index was 6.4 percent, comfortably below the 8 percent that research groups treat as the start of the healthy range. Only about one person in five reached 8 percent. Nearly four in five did not, and more than four in ten were under 6 percent. A small group, roughly one in twenty, sat beneath 4 percent, at the end of the scale researchers watch most closely. Women scored a little higher than men, a median of 6.5 percent against 5.8 percent, though neither group was close to the target.

The people in this data are not a careless crowd. They are people interested enough in their health to order a test, and many already ate fish or took a supplement. Being below target was still the normal result, not the exception. That is the first argument for measuring: a low omega-3 index has no symptoms you can feel day to day, so "I feel fine" tells you very little about where you actually stand.

Why the omega-6 to omega-3 ratio matters

EPA and DHA do not work alone. They share the body's enzymes with the omega-6 fatty acids, and the two families pull in opposite directions. Omega-6 compounds tend to be more inflammatory, omega-3 compounds less so.^[9][10] The balance between them closely reflects everyday diet.

Artemis Simopoulos estimates that humans evolved on a ratio close to 1:1, while a modern Western diet runs nearer 15:1.^[3] In her review, a 4:1 ratio was associated with a 70 percent lower total mortality in the secondary prevention of cardiovascular disease, and lower ratios tracked with reduced risk across several chronic conditions.^[3][4] Our test reads the ratio on a five-step scale and treats 3:1 to 5:1 as optimum, with the widely cited research target of 4:1 or below sitting at the lower, more favourable end of that band. Values under 3:1 are flagged as low, and anything above 5:1 as elevated. Our group had a median of 4.8, inside the optimum band but above the 4:1 research target. Half of all results fell within the 3:1 to 5:1 optimum band, while about three in ten reached 4:1 or below.

How do you actually improve this ratio? The answer is in the cell itself. The omega-6:3 ratio and the omega-3 index are closely linked, with a strong negative correlation in our data (r = -0.76). The main mechanism is the rise in omega-3: as EPA and DHA are incorporated into red blood cell membranes, they raise the membrane's omega-3 share and pull the overall ratio down.^[9][10] One important point follows: a high omega-6:3 ratio is in practice more a consequence of too little omega-3 than of too much omega-6 in the diet.

What the AA:EPA ratio says about inflammatory balance

The third marker compares arachidonic acid, an omega-6, with EPA, an omega-3. The two compete for the same enzymes, and EPA loses that competition when it is scarce. Because EPA forms less inflammatory products and arachidonic acid forms more,^[9][10] researchers use the AA:EPA ratio as a marker of inflammatory tone, where a lower number points to a less inflammatory profile.^[5]

The AA:EPA ratio divides arachidonic acid, a pro-inflammatory omega-6, by EPA, a calming omega-3, so it reads in one direction: lower is better. A low number means plenty of EPA relative to arachidonic acid; a high number means arachidonic acid dominates. Our test reads it on a five-step scale: reduced from 0.1 to 2.4, optimum from 2.5 to 11, slightly elevated from 11.1 to 14, elevated from 14 to 20, and high above 20. Research places the calmest, lowest-risk profile at around 3 or below, so a low result is a good result, and a result past 10 is drifting the wrong way even while it still counts as within range.^[5]

This is where our sample looked least balanced. The median AA:EPA ratio was 9.7, near the top of the optimum band rather than the favourable low end. Almost half of all results were above 10, and only about one in twenty reached 3 or below. In plain terms, for most of the people we tested, EPA was the fatty acid in short supply.

What AA:EPA you can expect at a given index

If the omega-3 index and the AA:EPA ratio read the same balance from two angles, it is fair to ask what one says about the other. Our data answers it directly. We grouped all 449 tests by omega-3 index and took the median AA:EPA in each band. The pattern is steep and consistent: as the index climbs, the inflammatory balance falls.

At an index of 8 percent or above, the median AA:EPA in our data was about 4 to 5. Below 4 percent it was close to 26, more than five times higher. These are medians, the typical value in each band rather than a fixed one, and around each of them individual results scatter widely. So your index points to a likely AA:EPA without pinning it down, which is the catch we turn to next.

Why you can't dose omega-3 from a label

By now the fix might seem obvious: if the number matters and most people fall short, why not skip the test, take a supplement, and move on? It is a fair instinct, but the data shows it is a weaker plan than it sounds. A supplement label tells you a dose. It does not tell you where you will end up, because people absorb and use omega-3 differently. And even your omega-3 index, useful as it is, does not fully pin down your AA:EPA ratio, the marker of your inflammatory balance. Among the people in our data at the very same 6 to 7 percent index, the AA:EPA ratio ran from about 4 to about 25.

This is the flip side of the band table, and the two fit together once you see how. On average a higher index does come with a lower AA:EPA, that trend is real. But it is only an average, and around it individual results scatter widely. Two people can share an index of 6.5 percent and sit a world apart on inflammatory balance, one near 5 and one near 20. The index counts only EPA and DHA, while AA:EPA also depends on the omega-6 side: how much omega-6 a person eats, how efficiently their body builds arachidonic acid from it, and the rest of their diet. The body builds arachidonic acid from the omega-6 in food through a chain of desaturation and elongation steps, the same enzyme pathway, run by the FADS genes, that is meant to turn plant ALA into EPA, so people who inherit different versions of those genes make very different amounts of it from the same diet. In our data the index accounts for only about half of the variation in AA:EPA from one person to the next; the rest comes from that omega-6 side. The band tells you what is typical at your index. Your own measured AA:EPA tells you where you actually are, which is why a label, or a single number, cannot stand in for a measured test.

Does flaxseed raise your omega-3 index?

Some people plan to cover omega-3 through plants, with flax, chia or walnuts. Those foods are rich in ALA, the plant form of omega-3. The problem is that ALA barely becomes the EPA and DHA your omega-3 index measures. Our test results show it plainly.

Across 449 membranes, the amount of ALA sitting in the membrane carried essentially no information about EPA or DHA status. ALA correlated with the omega-3 index at r = -0.09 and with EPA at r = -0.02, which is to say no relationship at all.

The biology behind it is well established. The human body converts only a small fraction of ALA into EPA, and less still into DHA. Controlled isotope studies in adults report exactly this: conversion to EPA is limited, and conversion to DHA is very low.^[7] Our membranes show the practical result, that the conversion is too small to register as omega-3 status.

People with plenty of plant omega-3 were no higher on the index than people with little. If the goal is to raise your omega-3 index, the evidence from our own samples points to EPA and DHA directly, from oily fish or an algae or fish oil, rather than to flax or chia. Plant omega-3 has its place in a diet, but it will not raise your omega-3 index.

How long does it take to raise your omega-3 index, and when to retest?

A test is most useful when it becomes a loop: measure, change your intake, measure again. The obvious question is how long to wait, and our retesters give a first answer. Among the 61 people who tested more than once, the typical gap was about eight months. Those who started low, in the 4 to 6 percent range, came back at a median of 6.3 percent, up from 5.2, and about eight in ten had risen.

There is a biological reason the wait matters. The index is carried in red blood cells, which live for about 120 days before the body replaces them, so as old cells retire and new ones form on your current diet, the number drifts to a new level over roughly three to four months rather than overnight. In a controlled study, six months of supplementation roughly doubled red-cell EPA and DHA, and red-cell levels closely mirror the heart's own omega-3 content, which is why the index is measured there.^[8] It also carries natural noise. In our retests the index swung by around 1.5 points in either direction even over short intervals, which means a retest at four weeks cannot separate a real change from ordinary variation. We would not read much into a test repeated that soon. Give it three to four months at least.

These are people who chose to test twice and we do not know exactly what each changed in between, so treat this as a realistic timescale rather than a measure of any single product.

How to raise a low omega-3 index

Two reasons for the shortfall show up repeatedly in the research. The first is intake. EFSA sets an adequate intake of 250 mg of EPA plus DHA a day for healthy adults, and a diet with little oily fish rarely reaches it. The second is under-dosing by the people who do supplement. A 2023 review argues that doses below a gram a day, together with the habit of never measuring blood levels, help explain why some omega-3 trials returned flat results, and its authors recommend measuring first and then adjusting intake toward a target.^[6] The logic is simple: you cannot correct a number you have never seen.

The approach starts with a measurement rather than a guess. A dried blood spot test turns a few drops from a fingertip into a real omega-3 index and the full fatty acid panel, both ratios included, and a retest after a few months shows whether anything has changed. From there the main lever is EPA and DHA, through oily fish two or three times a week where that is realistic and a measured supplement to fill the gap where it is not. EPA and DHA contribute to the normal function of the heart.^* DHA also contributes to the maintenance of normal brain function and normal vision.^**

It also helps to watch the form rather than the headline percentage on a label, since a very high concentration usually signals heavier processing rather than a better oil. We judge an oil by how close it stays to its natural form, not by the biggest number, a point we unpack in our note on omega-3 from algae or from fish. Easing off the omega-6 side matters too, because cutting back on refined cooking oils shifts the ratio from both ends at once. For the fuller picture of how that balance works, see our explainer on the omega-3 nutrients we should not forget in our diet, or browse our omega-3 range.

Key takeaways

About this data: results come from Trime's omega-3 dried blood spot programme, analysed with the OmegaMetrix HS-Omega-3 Index panel of 26 fatty acids. The figures cover 449 processed results as of April 2026. The group was predominantly Czech and about 79 percent female, with a median age near 38. These are people who chose to test, not a population-representative sample, so read the percentages as a signal rather than a national average. Don't trust the summary. The full panel is on your own report.

^* A beneficial effect is obtained with a daily intake of 250 mg of EPA and DHA.
^** A beneficial effect is obtained with a daily intake of 250 mg of DHA.

Sources

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[4] Simopoulos AP. Genetic Variation, Diet, Inflammation, and the Risk for COVID-19. Lifestyle Genom. 2021. https://doi.org/10.1159/000513886

[5] Nelson JR, Raskin S. The eicosapentaenoic acid:arachidonic acid ratio and its clinical utility in cardiovascular disease. Postgrad Med. 2019. https://doi.org/10.1080/00325481.2019.1607414

[6] Hamilton-Craig C, Kostner K, Colquhoun D, Nicholls SJ. Omega-3 fatty acids and cardiovascular prevention: is the jury still out? Intern Med J. 2023. https://doi.org/10.1111/imj.16283

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[8] Harris WS, Sands SA, Windsor SL, et al. Omega-3 fatty acids in cardiac biopsies from heart transplantation patients: correlation with erythrocytes and response to supplementation. Circulation. 2004. https://doi.org/10.1161/01.CIR.0000142292.10048.B2

[9] Calder PC. Omega-3 fatty acids and inflammatory processes. Nutrients. 2010. https://doi.org/10.3390/nu2030355

[10] Calder PC. Marine omega-3 fatty acids and inflammatory processes: effects, mechanisms and clinical relevance. Biochim Biophys Acta. 2015. https://doi.org/10.1016/j.bbalip.2014.08.010