--- title: "Omega-3 Index Test — Evidence, Benefits & Where to Buy | Magellan" description: "Omega-3 Index Test — The Omega-3 Index is a blood biomarker defined as the amount of the long-chain marine omega-3 fatty acids eicosapentaenoic acid…" url: "https://magellanlongevity.com/p/143.md" canonical: "https://magellanlongevity.com/p/143.html" html: "https://magellanlongevity.com/p/143.html" type: "product" section: "Diagnostics & Epigenetic Tests" evidence_grade: "Measurement tool" evidence_tier: "tool" citations: 22 product_id: 143 price_usd: 54.95 updated: 2026-09-02 author: "Gabriel Radu, DO" author_credentials: "Physiatrist (PM&R). NY medical license 275110. NPI 1376861765." publisher: "Magellan Longevity" content_format: "markdown" license: "Educational content — not medical advice" --- # Omega-3 Index Test [Home](https://magellanlongevity.com/) › [Diagnostics & Epigenetic Tests](https://magellanlongevity.com/c/2.md) › Omega-3 Index Test **HTML version:** https://magellanlongevity.com/p/143.html · **In the Magellan app:** https://magellanlongevity.com/#/product/143 ## Key facts | Field | Value | | --- | --- | | Product | Omega-3 Index Test | | Category | [Diagnostics & Epigenetic Tests](https://magellanlongevity.com/c/2.md) | | Evidence grade | Measurement tool (B) | | Peer-reviewed citations | 22 | | Typical listed price | $54.95 (check the live price) | | Where to buy | [Search Amazon](https://www.amazon.com/s?k=Omega-3%20Index%20Test&tag=magellanlong-20) | | Catalog ID | 143 | ## What it is The Omega-3 Index is a blood biomarker defined as the amount of the long-chain marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contained in red blood cell (erythrocyte) membranes, expressed as a percentage of total fatty acids. It was proposed by Harris and von Schacky in 2004 and is determined from a small blood sample (including a finger-prick dried-blood spot) using a standardized analytical method (the HS-Omega-3 Index). Because erythrocyte fatty-acid composition turns over slowly, the index reflects a person's long-term EPA + DHA status and tissue levels rather than recent intake, with commonly cited target values of 8-11%. ## Its role in longevity In prospective cohort studies and pooled analyses spanning dozens of cohorts, higher blood levels of EPA + DHA have been consistently associated with lower all-cause and cardiovascular mortality - across ten cohorts an Omega-3 Index near 8% carried roughly 30% lower fatal coronary heart disease risk than one near 4% - and a low index meets proposed criteria for a novel cardiovascular risk marker; lower erythrocyte omega-3 levels have also been linked to smaller brain volumes and poorer cognitive measures during aging. However, several large randomized supplementation trials produced neutral results for clinical endpoints, a discrepancy attributed partly to trial-design and bioavailability issues rather than to a lack of biomarker relevance, and a 2024 UK Biobank analysis tied regular fish-oil use in people without cardiovascular disease to higher atrial fibrillation and stroke risk. Much of the strongest evidence is observational association rather than proof that raising the index itself causes better outcomes. This evidence describes the EPA + DHA biomarker (the Omega-3 Index) and its measurement in general, not this specific commercial test product. ## Evidence grade: Measurement tool - **What the grade means:** Graded as an instrument: how accurately it measures, and whether measuring it changes anything. - **Dose used in studies:** Once to find your baseline, then again about 4 months after changing oily fish intake or starting a supplement - red cell fatty acids turn over slowly and anything sooner is reading noise. Most people sit around 4-5%; the level associated with lowest risk in the cohort work is roughly 8% or above. - **What this grade does not say:** This is the one test on the list where the analyte and the method were developed together and both hold up. Pooled across 17 prospective cohorts, higher blood omega-3 levels tracked lower total and cause-specific mortality, the Framingham data point the same way, and the index adds predictive information on top of the pooled cohort equation - and unlike a serum fatty acid, red cell membrane composition is a stable several-month average rather than a snapshot of last night's dinner. Two things to hold in mind anyway - the evidence is observational, and people with a high Omega-3 Index differ from people with a low one in many ways, and the supplement trials designed to test whether raising it changes outcomes have come out mixed rather than clean, so a low number is a reason to eat more oily fish and not proof that a capsule will buy you the associated risk. And the index is a proprietary measure run by the laboratory whose founder developed it and co-authors much of the supporting literature - that is disclosed rather than hidden, but you should know it is not an independently standardised assay with an external reference method behind it. ## In the news - **People with a higher Omega-3 Index lived longer than others, study shows** — News-Medical 2021 [Read it](https://www.news-medical.net/news/20210423/People-with-a-higher-Omega-3-Index-lived-longer-than-others-study-shows.aspx) > It showed that those people with higher omega-3 EPA and DHA blood levels (i.e., Omega-3 Index) lived longer than those with lower levels. - **New study shows people with a high Omega-3 index less likely to die prematurely** — EurekAlert! (AAAS) 2021 [Read it](https://www.eurekalert.org/news-releases/568880) > When FORCE researchers examined the risk for death from any cause, the people who had the highest EPA+DHA levels (i.e., at the 90th percentile) had a statistically significant, 13% lower risk for death than people with EPA+DHA levels in the 10th percentile. - **Low Omega-3 Index as powerful a predictor of early death as smoking: Study** — NutraIngredients 2021 [Read it](https://www.nutraingredients.com/Article/2021/06/28/Low-Omega-3-Index-as-powerful-a-predictor-of-early-death-as-smoking-Study/) > Low levels of EPA and DHA omega-3s in red blood cell membranes may have a similar predictive power of early death to that of the well-established standard risk factors, such as smoking, says a new analysis. ## The research Peer-reviewed studies on the active compound. Quotes are verbatim from the cited abstract. Research describes the active mechanism and is not a claim about this specific product. ### Cited studies 1. **Evidence: Erythrocyte EPA+DHA percentage** Nutrients 2021 · [PMID 33806218](https://pubmed.ncbi.nlm.nih.gov/33806218/) · [DOI 10.3390/nu13041074](https://doi.org/10.3390/nu13041074) > a lower Omega-3 Index was associated with increased risk for total mortality and ischemic stroke 2. **Omega-3 fatty acids and mortality in patients referred for coronary angiography** Atherosclerosis 2016 · [PMID 27397734](https://pubmed.ncbi.nlm.nih.gov/27397734/) · [DOI 10.1016/j.atherosclerosis.2016.06.049](https://doi.org/10.1016/j.atherosclerosis.2016.06.049) > EPA and DHA were associated with reduced mortality independent of other risk factors 3. **Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies.** Nat Commun 2021 · [PMID 33888689](https://pubmed.ncbi.nlm.nih.gov/33888689/) · [DOI 10.1038/s41467-021-22370-2](https://doi.org/10.1038/s41467-021-22370-2) > risk for death from all causes was significantly lower (by 15-18%, at least p < 0.003) in the highest vs the lowest quintile for circulating long chain (20-22 carbon) omega-3 fatty acids (eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids). 4. **The Omega-3 Index: a new risk factor for death from coronary heart disease?** Prev Med 2004 · [PMID 15208005](https://pubmed.ncbi.nlm.nih.gov/15208005/) · [DOI 10.1016/j.ypmed.2004.02.030](https://doi.org/10.1016/j.ypmed.2004.02.030) > The Omega-3 Index was inversely associated with risk for CHD mortality. An Omega-3 Index of > or = 8% was associated with the greatest cardioprotection, whereas an index of < or = 4% was associated with the least. 5. **Erythrocyte long-chain omega-3 fatty acid levels are inversely associated with mortality and with incident cardiovascular disease: The Framingham Heart Study.** J Clin Lipidol 2018 · [PMID 29559306](https://pubmed.ncbi.nlm.nih.gov/29559306/) · [DOI 10.1016/j.jacl.2018.02.010](https://doi.org/10.1016/j.jacl.2018.02.010) > Those in the highest (>6.8%) compared to those in the lowest Omega-3 Index quintiles (<4.2%) had a 34% lower risk for death from any cause and 39% lower risk for incident CVD. 6. **Red blood cell polyunsaturated fatty acids and mortality in the Women's Health Initiative Memory Study.** J Clin Lipidol 2017 · [PMID 28391893](https://pubmed.ncbi.nlm.nih.gov/28391893/) · [DOI 10.1016/j.jacl.2016.12.013](https://doi.org/10.1016/j.jacl.2016.12.013) > Higher RBC levels of marine n-3 PUFAs were associated with reduced risk for all-cause mortality. These findings support the beneficial relationship between the Omega-3 Index and health outcomes. 7. **Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort.** Am J Clin Nutr 2021 · [PMID 34134132](https://pubmed.ncbi.nlm.nih.gov/34134132/) · [DOI 10.1093/ajcn/nqab195](https://doi.org/10.1093/ajcn/nqab195) > In this community-based population in their mid-60s, RBC FA patterns were as predictive of risk for death during the next 11 y as standard risk factors. Replication is needed in other cohorts to validate this FA fingerprint as a predictor of all-cause mortality. 8. **Red blood cell ω-3 fatty acid levels and markers of accelerated brain aging.** Neurology 2012 · [PMID 22371413](https://pubmed.ncbi.nlm.nih.gov/22371413/) · [DOI 10.1212/WNL.0b013e318249f6a9](https://doi.org/10.1212/WNL.0b013e318249f6a9) > Lower RBC DHA levels are associated with smaller brain volumes and a "vascular" pattern of cognitive impairment even in persons free of clinical dementia. 9. **Associations of erythrocyte omega-3 fatty acids with cognition, brain imaging and biomarkers in the Alzheimer's disease neuroimaging initiative: cross-sectional and longitudinal retrospective analyses.** Am J Clin Nutr 2022 · [PMID 36253968](https://pubmed.ncbi.nlm.nih.gov/36253968/) · [DOI 10.1093/ajcn/nqac236](https://doi.org/10.1093/ajcn/nqac236) > Longitudinally, low ω-3 index was associated with greater Aβ accumulation and WMS cognitive decline but unexpectedly with lower total ADAS-Cog cognitive decline. 10. **Impact of Omega-3 Fatty Acid Supplementation on Memory Functions in Healthy Older Adults.** J Alzheimers Dis 2016 · [PMID 26890759](https://pubmed.ncbi.nlm.nih.gov/26890759/) · [DOI 10.3233/JAD-150886](https://doi.org/10.3233/JAD-150886) > Omega-3 index increased significantly in the LC-n3-FA group compared with the placebo group. Moreover, recall of object locations was significantly better after LC-n3-FA supplementation compared with placebo. 11. **Brain atrophy in cognitively impaired elderly: the importance of long-chain ω-3 fatty acids and B vitamin status in a randomized controlled trial.** Am J Clin Nutr 2015 · [PMID 25877495](https://pubmed.ncbi.nlm.nih.gov/25877495/) · [DOI 10.3945/ajcn.114.103283](https://doi.org/10.3945/ajcn.114.103283) > In subjects with high baseline ω-3 fatty acids (>590 μmol/L), B vitamin treatment slowed the mean atrophy rate by 40.0% compared with placebo (P = 0.023). 12. **Omega-3 polyunsaturated fatty acid supplementation reduces blood pressure but not renal vasoconstrictor response to orthostatic stress in healthy older adults.** Physiol Rep 2018 · [PMID 29673104](https://pubmed.ncbi.nlm.nih.gov/29673104/) · [DOI 10.14814/phy2.13674](https://doi.org/10.14814/phy2.13674) > In conclusion, FO supplementation attenuates the mean BP response but does not affect the renal vasoconstrictor response to orthostatic stress in older adults. 13. **Omega-3 index and cardiovascular health.** Nutrients 2014 · [PMID 24566438](https://pubmed.ncbi.nlm.nih.gov/24566438/) · [DOI 10.3390/nu6020799](https://doi.org/10.3390/nu6020799) > blood levels of EPA + DHA are frequently assessed in erythrocytes, using the HS-Omega-3 Index® methodology. A low Omega-3 Index fulfills the current criteria for a novel cardiovascular risk factor. 14. **Omega-3 index in 2018/19.** Proc Nutr Soc 2020 · [PMID 32389149](https://pubmed.ncbi.nlm.nih.gov/32389149/) · [DOI 10.1017/S0029665120006989](https://doi.org/10.1017/S0029665120006989) > Recent epidemiologic data further support the relevance of the omega-3 index in the cardiovascular field, since total mortality, cardiovascular mortality, cardiovascular events such as myocardial infarction or stroke, or blood pressure all correlate inversely with the omega-3 index. 15. **Ω-3 index as a prognosis tool in cardiovascular disease.** Curr Opin Clin Nutr Metab Care 2017 · [PMID 28768293](https://pubmed.ncbi.nlm.nih.gov/28768293/) · [DOI 10.1097/MCO.0000000000000404](https://doi.org/10.1097/MCO.0000000000000404) > EPA and DHA in RBCs were associated with reduced mortality in a prospective study of patients with cardiac disease; the strongest association was with EPA. 16. **n-3 Fatty acids and risk for fatal coronary disease.** Proc Nutr Soc 2019 · [PMID 30837013](https://pubmed.ncbi.nlm.nih.gov/30837013/) · [DOI 10.1017/S0029665118002902](https://doi.org/10.1017/S0029665118002902) > our studies in the Framingham Heart Study and in the Women's Health Initiative Memory Study have demonstrated significant inverse relations between erythrocyte EPA + DHA levels (i.e. the Omega-3 Index) and total mortality. 17. **Omega-3 fatty acids in cardiovascular disease--an uphill battle.** Prostaglandins Leukot Essent Fatty Acids 2014 · [PMID 24935800](https://pubmed.ncbi.nlm.nih.gov/24935800/) · [DOI 10.1016/j.plefa.2014.05.004](https://doi.org/10.1016/j.plefa.2014.05.004) > A standardized way of determining levels is the Omega-3 Index, which is the percentage of EPA+DHA of a total of 26 fatty acids measured in erythrocytes. According to current criteria, a low Omega-3 Index is a cardiovascular risk factor. 18. **Omega-3 fatty acids in heart disease-why accurately measured levels matter.** Neth Heart J 2023 · [PMID 36795219](https://pubmed.ncbi.nlm.nih.gov/36795219/) · [DOI 10.1007/s12471-023-01759-2](https://doi.org/10.1007/s12471-023-01759-2) > An Omega-3 Index in the target range of 8-11% is associated with lower total mortality, fewer major adverse cardiac and other cardiovascular events. 19. **The omega-3 index: from biomarker to risk marker to risk factor.** Curr Atheroscler Rep 2009 · [PMID 19852881](https://pubmed.ncbi.nlm.nih.gov/19852881/) · [DOI 10.1007/s11883-009-0062-2](https://doi.org/10.1007/s11883-009-0062-2) > Multiple lines of evidence link reduced tissue and/or blood levels of omega-3 fatty acids, as reflected in the erythrocyte eicosapentaenoic acid plus docosahexaenoic acid level (ie, the omega-3 index), with increased risk for coronary heart disease, especially sudden cardiac death. 20. **Why docosapentaenoic acid is not included in the Omega-3 Index.** Prostaglandins Leukot Essent Fatty Acids 2018 · [PMID 30103927](https://pubmed.ncbi.nlm.nih.gov/30103927/) · [DOI 10.1016/j.plefa.2018.06.003](https://doi.org/10.1016/j.plefa.2018.06.003) > In epidemiologic studies, erythrocyte DPA did not predict risk for total mortality, sudden cardiac death, or other relevant cardiovascular events, and, more importantly, did not improve prediction of these events when included along with EPA and DHA, the original Omega-3 Index. 21. **The Omega-3 Index and relative risk for coronary heart disease mortality: Estimation from 10 cohort studies.** Atherosclerosis 2017 · [PMID 28511049](https://pubmed.ncbi.nlm.nih.gov/28511049/) > Across 10 cohort studies, each 1-SD (about 2.1%) higher Omega-3 Index was associated with 15% lower fatal CHD risk, equivalent to roughly 30% lower risk at an index of about 8% versus 4%. 22. **ω-3 Polyunsaturated Fatty Acid Biomarkers and Coronary Heart Disease: Pooling Project of 19 Cohort Studies.** JAMA internal medicine 2016 · [PMID 27357102](https://pubmed.ncbi.nlm.nih.gov/27357102/) > Pooling 19 cohorts (45,637 participants), each 1-SD higher blood EPA/DHA biomarker level was associated with about 9-13% lower risk of fatal coronary heart disease. ## Where to buy [Search Amazon for Omega-3 Index Test](https://www.amazon.com/s?k=Omega-3%20Index%20Test&tag=magellanlong-20) — affiliate search link. ## Structured data ```json {"@context":"https://schema.org","@graph":[{"@type":"ItemPage","@id":"https://magellanlongevity.com/p/143.html#page","url":"https://magellanlongevity.com/p/143.html","name":"Omega-3 Index Test","description":"The Omega-3 Index is a blood biomarker defined as the amount of the long-chain marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic…","inLanguage":"en","isPartOf":{"@type":"WebSite","name":"Magellan Longevity","url":"https://magellanlongevity.com/"},"author":{"@type":"Person","name":"Gabriel Radu, DO","jobTitle":"Physiatrist (PM&R)","identifier":[{"@type":"PropertyValue","name":"NPI","value":"1376861765"},{"@type":"PropertyValue","name":"NY medical license","value":"275110"}]},"publisher":{"@type":"Organization","name":"Magellan Longevity","url":"https://magellanlongevity.com/"},"encoding":{"@type":"MediaObject","encodingFormat":"text/markdown","contentUrl":"https://magellanlongevity.com/p/143.md"},"dateModified":"2026-09-02"},{"@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://magellanlongevity.com/"},{"@type":"ListItem","position":2,"name":"Diagnostics & Epigenetic Tests","item":"https://magellanlongevity.com/c/2.html"},{"@type":"ListItem","position":3,"name":"Omega-3 Index Test","item":"https://magellanlongevity.com/p/143.html"}]},{"@type":"Product","@id":"https://magellanlongevity.com/p/143.html#product","name":"Omega-3 Index Test","category":"Diagnostics & Epigenetic Tests","url":"https://magellanlongevity.com/p/143.html","description":"The Omega-3 Index is a blood biomarker defined as the amount of the long-chain marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contained in red blood cell (erythrocyte) membranes, expressed as a percentage of total fatty acids. It was proposed by Harris and…","additionalProperty":[{"@type":"PropertyValue","name":"Evidence grade","value":"Measurement tool"}],"offers":{"@type":"Offer","priceCurrency":"USD","price":"54.95","url":"https://www.amazon.com/s?k=Omega-3%20Index%20Test&tag=magellanlong-20","availability":"https://schema.org/InStock"}}]} ``` ## Related on Magellan Longevity - [Grip-Strength Dynamometer](https://magellanlongevity.com/p/153.md) — Across large prospective cohorts and meta-analyses, lower grip strength is consistently associated with… - [Saliva Cortisol Stress Test](https://magellanlongevity.com/p/149.md) — Across large studies, dysregulated cortisol patterns track with worse health: a meta-analysis found flatter… - [GGT Liver-Health Test](https://magellanlongevity.com/p/156.md) — Large prospective cohorts and meta-analyses consistently link higher serum GGT, even within the reference… - [Fasting Insulin / HOMA-IR Kit](https://magellanlongevity.com/p/145.md) — Higher fasting insulin and HOMA-IR reflect greater insulin resistance, a central feature of metabolic… - [hs-CRP Inflammation Test](https://magellanlongevity.com/p/142.md) — Across large prospective cohorts and meta-analyses, higher hs-CRP is consistently associated with increased… - [All Diagnostics & Epigenetic Tests](https://magellanlongevity.com/c/2.md) - [Evidence-based longevity supplements](https://magellanlongevity.com/longevity-supplements.md) - [Longevity research map](https://magellanlongevity.com/longevity-research-map.html) ## Scope and disclosures Educational information, not medical advice. Nothing here is intended to diagnose, treat, cure, or prevent any disease. Talk to your physician before starting any supplement or device, especially if you are pregnant, nursing, or taking medication. Editorial firewall: evidence grades are assigned from the published research and are independent of any affiliate commission. As an Amazon Associate, Magellan Longevity earns from qualifying purchases. Reviewed for accuracy by a board-certified physician (DO).