What it measures
Arachidonic acid (AA), an omega-6 fat, divided by eicosapentaenoic acid (EPA), an omega-3 fat, both measured in the same blood sample. It shows the balance between the two.
Why people test it
- Looked at by people tracking the balance of omega-6 and omega-3 fats in their diet.
- Usually reported as part of a wider fatty acid profile, alongside the omega-3 index.
- Checked again after a change in diet to see how the balance shifts.
Typical range
There is no single agreed range. Ranges vary by lab, method (red cells, whole blood or plasma), age and sex, and your report shows the lab's own range.
Finger-prick or vein?
A finger-prick sample is usually fine, as fatty acid tests are often run on dried blood spots. Vein draws are offered too.