Omega-3 Index / Fatty Acids
Measure of omega-3 fatty acids in blood
5 providers include this
Advanced / Specialty Markers
Target:>8%, Intermediate:4-8%, Undesirable:<4%
What is Omega-3 Index / Fatty Acids?
The Omega-3 Index measures the percentage of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in red blood cell membranes. It reflects your long-term omega-3 fatty acid status over the past 3-4 months, similar to how HbA1c reflects glucose control. This biomarker was developed by Dr. William Harris and is considered the gold standard for assessing omega-3 status.
EPA and DHA are essential omega-3 fatty acids that must be obtained from diet or supplements—your body cannot produce them efficiently from plant-based ALA (alpha-linolenic acid). They are structural components of every cell membrane in your body, particularly concentrated in the brain (60% of brain tissue is fat, much of it DHA) and heart. An Omega-3 Index below 8% is associated with increased risk of sudden cardiac death, cognitive decline, and systemic inflammation.
The target Omega-3 Index for longevity optimization is >8%, though most Americans have levels between 4-5%. Achieving this typically requires consuming 2-3 grams of EPA+DHA daily from fatty fish (salmon, sardines, mackerel) or high-quality fish oil supplements. The ratio of omega-6 to omega-3 fatty acids also matters—the modern Western diet has a ratio of 15-20:1 when optimal is closer to 4:1 or lower.
Why the Omega-3 Index Matters for Longevity
- Cardiovascular protection:An Omega-3 Index >8% is associated with a 30% reduction in risk of sudden cardiac death and significantly lower triglycerides. EPA and DHA reduce inflammation, stabilize heart rhythm, and improve endothelial function.
- Brain health and cognition:DHA is the primary structural fat in the brain. Higher Omega-3 Index is associated with larger brain volume, better cognitive function, and reduced risk of Alzheimer's disease. Low levels accelerate brain aging by 1-2 years.
- Anti-inflammatory effects:EPA and DHA are precursors to resolvins and protectins—powerful anti-inflammatory molecules that resolve chronic inflammation without suppressing immune function. This is critical for longevity since chronic inflammation drives most age-related diseases.
- Mental health:Higher Omega-3 Index is associated with lower rates of depression, anxiety, and improved mood stability. EPA in particular has potent antidepressant effects comparable to some medications at doses of 1-2 grams daily.
- Eye health:DHA is highly concentrated in the retina. Adequate levels protect against age-related macular degeneration (AMD), the leading cause of blindness in older adults.
- Cellular aging:Higher Omega-3 Index is associated with longer telomeres (protective caps on chromosomes that shorten with age). Each 1% increase in Omega-3 Index may slow cellular aging by several months.
Optimal vs Standard Ranges
Optimal (Longevity)>8%▼
- Exceptional omega-3 status associated with maximal cardiovascular and brain protection
- This level significantly reduces risk of sudden cardiac death, cognitive decline, and systemic inflammation
- Requires consistent intake of 2-3g EPA+DHA daily
Good (Standard)6-8%▼
- Adequate omega-3 status with good cardiovascular and cognitive protection
- Most benefits are achieved in this range, though higher is better for longevity optimization
Acceptable (Functional)4-6%▼
- Below optimal omega-3 status
- This is where most Americans fall
- Increased risk of cardiovascular events, cognitive decline, and inflammatory conditions
- Supplementation strongly recommended
Suboptimal (Standard)<4%▼
- Severely deficient omega-3 status associated with significantly increased risk of sudden cardiac death, depression, cognitive impairment, and accelerated aging
- Immediate intervention required
Scientific Evidence
The Omega-3 Index responds slowly to dietary changes—it takes 3-4 months to reach steady state after starting supplementation. Retest every 3-6 months to ensure you're maintaining >8%. Individual absorption varies significantly;some people need 3-4g EPA+DHA daily to reach target levels.
Consider prescription omega-3s
For those with very high triglycerides (>500 mg/dL) or difficulty absorbing supplements, prescription omega-3 products like Vascepa (icosapent ethyl, 4g EPA daily) or Lovaza (EPA+DHA ethyl esters) may be appropriate. These are FDA-approved for cardiovascular risk reduction and covered by insurance.
Very low:Rare as isolated deficiency
Most people with low Omega-3 Index are asymptomatic initially. However, chronic deficiency may manifest as:dry/rough skin, brittle hair and nails, difficulty concentrating or brain fog, mood issues (depression, anxiety, irritability), joint pain or stiffness, poor wound healing, frequent infections. Note:These symptoms are non-specific and can have many causes.
High:Not applicable
Omega-3 Index cannot be "too high"in a pathological sense. Very high intake (>5g EPA+DHA daily) may cause:mild fishy aftertaste or burping, slightly increased bleeding time (though not clinically significant in most people), mild gastrointestinal upset. These are generally mild and dose-dependent, not dangerous.
Low omega-3 intake
Source:Causes of Low Omega-3 Index
Low dietary intake of fatty fish (<1 serving per week)|No supplementation with fish oil or algae-based omega-3s|High intake of omega-6 fatty acids from processed foods and vegetable oils (competes with omega-3 absorption)|Genetic variations affecting omega-3 metabolism (some people convert dietary omega-3s less efficiently)|Chronic inflammatory conditions or malabsorption disorders (Crohn's, celiac, IBD) that impair fat absorption|Medications that impair fat absorption (Orlistat, bile acid sequestrants)
N/A
Source:Causes of High Omega-3 Index
Which Providers Test Omega-3 Index / Fatty Acids?
Full Provider Comparison
| Provider | Includes | Annual Cost | Biomarkers |
|---|---|---|---|
 Superpower | ✓ | $199 | 100+ (150 with ratios) |
 WHOOP Advanced Labs | — | $349 | 65 |
 Labcorp OnDemand | — | $398 | 30+ |
| — | $486 | 40+ | |
| — | $444 | 288 | |
| — | $349 | 100+ | |
| — | $761 | 54 | |
 Function Health | ✓ | $365 | 160+ |
| — | $250 | 65 | |
| — | $495 | 70+ | |
| ✓ | $895 | 100+ | |
| ✓ | $1950 | 150+ | |
| — | $375 | 80+ | |
| — | $Varies | 75+ | |
| — | $190 | 100+ | |
| — | $99 | 50 | |
| — | $124 | 60 | |
| — | $199 | 50 | |
| — | $499 | 120+ | |
| — | $4188 | 70-80+ | |
| — | $375 | 85 | |
| ✓ | $700 | 128 |
Frequently Asked Questions
What is Omega-3 Index / Fatty Acids?
Measure of omega-3 fatty acids in blood
What is the optimal range for Omega-3 Index / Fatty Acids?
The standard reference range for Omega-3 Index / Fatty Acids is Target:>8%, Intermediate:4-8%, Undesirable:<4%. Optimal ranges may differ based on individual health goals and expert recommendations.
Which blood test providers include Omega-3 Index / Fatty Acids?
5 out of 22 blood testing providers include Omega-3 Index / Fatty Acids in their panels. This biomarker has limited availability.
What category does Omega-3 Index / Fatty Acids fall under?
Omega-3 Index / Fatty Acids is categorized under Advanced / Specialty Markers. This category includes biomarkers that help assess related aspects of health and wellness.
Medical Disclaimer
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
Last reviewed:2026-02-20