Eicosapentaenoic Acid (EPA) is an omega-3 polyunsaturated fatty acid commonly found in fish oil. Its use for migraine is primarily based on a scientific rationale rather than tradition. EPA and other omega-3 fatty acids are thought to modulate inflammation, neuronal excitability, and vascular function, all of which have been implicated in migraine pathophysiology. However, the clinical evidence specifically supporting EPA for migraine prevention or treatment is limited and inconsistent.

A few small randomized controlled trials have assessed omega-3 supplementation (usually as a combination of EPA and DHA) for migraine, with mixed results. Some studies have shown modest reductions in headache frequency or severity, while others have found no significant effect compared to placebo. Meta-analyses and systematic reviews generally conclude that the evidence is insufficient or of low quality, and that larger, well-designed studies are needed. The proposed mechanism involves EPA's anti-inflammatory properties, potentially reducing the neurogenic inflammation associated with migraine attacks.

In summary, while there is a scientific rationale and some preliminary evidence that EPA (as part of omega-3 supplementation) might help with migraines, the overall clinical evidence is weak and does not support its routine use for this purpose at this time.