Prioritize EPA over DHA when choosing a supplement

For mood specifically, choose a fish oil with at least 60% EPA by weight — the EPA fraction drives antidepressant effects.

Why it works

EPA and DHA have different downstream effects. DHA is structurally important for neuronal membranes but does not show consistent antidepressant effects in trials. EPA appears to reduce neuroinflammation by modulating the same eicosanoid pathways that many antidepressants influence indirectly. Meta-analyses that stratified by EPA fraction found that formulas providing more than 60% EPA drove the effect; mixed or DHA-dominant formulas showed minimal benefit for mood.

How to do it

1. Read the supplement label for EPA and DHA amounts; EPA should exceed DHA for mood applications.
2. Aim for 1–2 g EPA per day — a common dose range in clinical trials showing mood effects.
3. Take with a fatty meal to improve absorption.
4. Give it 6–8 weeks before assessing mood effects — membrane composition changes slowly.

Evidence

A meta-analysis of RCTs found omega-3 supplements with a higher proportion of EPA show statistically significant antidepressant effects; DHA-dominant supplements did not. (rct)

Effect sizes are modest; trials often include people with clinical depression, and effects in general population mood may be smaller. This is not a substitute for professional mental health care.

Sources

• Sublette et al. (2011), Meta-analysis of the effects of eicosapentaenoic acid (EPA) on depression, Journal of Clinical Psychiatry

Common mistake

Buying a generic "fish oil" or "omega-3" supplement dominated by DHA and expecting mood benefits — the EPA fraction is what matters for mood, not total omega-3 content.