What is the laboratory test for Omega-3 (fatty acids) levels?

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Last updated: April 29, 2025 • View editorial policy

From the Guidelines

The test for omega-3 fatty acid levels is called the Omega-3 Index test. This blood test measures the percentage of EPA and DHA (the two main omega-3 fatty acids) in red blood cell membranes, providing an accurate assessment of your long-term omega-3 status. According to the most recent evidence, the Omega-3 Index test is a valuable tool for assessing omega-3 levels 1. The test typically requires a small blood sample, often collected via a finger prick, which can be done at a healthcare provider's office or through at-home test kits that you mail to a laboratory. Results are usually reported as a percentage, with an optimal Omega-3 Index considered to be 8% or higher, while levels below 4% are associated with increased health risks. This test is valuable because omega-3 levels can't be accurately determined through dietary intake estimates alone, and knowing your specific levels can help guide supplementation decisions or dietary changes. Some healthcare providers may also order a more comprehensive fatty acid profile test that includes omega-3 measurement along with other fatty acids to provide a more complete picture of your fatty acid status. Key points to consider when interpreting Omega-3 Index test results include:

  • Optimal levels: 8% or higher
  • Increased health risks: levels below 4%
  • Test methodology: blood sample collected via finger prick or venipuncture
  • Result interpretation: percentage of EPA and DHA in red blood cell membranes.

From the Research

Omega-3 Index Test

The test for omega-3 lab is called the Omega-3 Index test, which measures the percentage of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in erythrocytes (red blood cells) [ 2 ].

Key Points

  • The Omega-3 Index is a standardized method for measuring EPA and DHA levels in the blood [ 3 ].
  • The test is used to assess an individual's omega-3 status and determine their risk for chronic diseases such as cardiovascular disease [ 4 ].
  • The optimal level for the Omega-3 Index is 8% or greater [ 3 ].
  • The test can be used to monitor the effectiveness of omega-3 supplements in improving an individual's omega-3 status [ 5 ].
  • The HS-Omega-3 Index is a specific method for measuring the Omega-3 Index, which has been shown to correlate with a reduction in cardiovascular and other risk factors [ 5 ].

Factors Affecting Omega-3 Index

  • Dose and duration of omega-3 supplementation [ 4 ].
  • Chemical formulation of the supplement (e.g. triglyceride vs. ethyl ester) [ 6 ].
  • Baseline omega-3 status [ 6 ].

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.