EPA (eicosapentaenoic acid) is an omega-3 fatty acid your body cannot make in meaningful amounts on its own, so you have to get it from food or supplements. It's found naturally in fatty fish like salmon, mackerel, and sardines, as well as in marine algae. Unlike its omega-3 cousin DHA, EPA is especially active as an anti-inflammatory agent and mood regulator, making it uniquely valuable for mental and cardiovascular health.

EPA works mainly by dialing down inflammation. It competes with a pro-inflammatory fat called arachidonic acid, nudging your body to make less of the signaling molecules that drive chronic inflammation. It also helps lower blood triglycerides, supports the flexibility of cell membranes, and appears to influence serotonin signaling in the brain — which is likely why it's so helpful for mood.

EPA comes in regular fish oil (combined with DHA), high-EPA concentrates (at least 60% EPA), prescription-strength pure EPA ethyl ester, and vegan algae-based formulas. Triglyceride-form fish oil is absorbed slightly better than ethyl ester form, and taking any form with a fatty meal meaningfully improves absorption.

• Depression and low mood
• High triglycerides
• Heart disease risk
• Chronic inflammation
• Anxiety
• Rheumatoid arthritis and joint pain
• Dry eye syndrome
• ADHD (children and adults)
• Post-heart attack recovery
• Metabolic syndrome

• Recurrent cardiovascular events (heart attack, stroke) in high-risk individuals with elevated triglycerides
• Progression of atherosclerosis in statin-treated patients
• Preterm birth (when taken during pregnancy — evidence emerging)
• Worsening of depressive episodes when used as maintenance support

• Mackerel — One of the richest sources of EPA per serving — a 3.5 oz portion delivers roughly 900mg of EPA, along with DHA. Atlantic mackerel is especially potent and low in mercury.
• Wild-caught salmon — A 3.5 oz serving of wild Atlantic salmon provides around 600–800mg of EPA. Wild-caught is higher in omega-3s than farmed, and it's one of the most widely available fatty fish.
• Sardines (canned or fresh) — Sardines pack around 400–500mg of EPA per 3.5 oz serving and are extremely low in mercury given their small size. Canned in water or olive oil both work well.
• Herring — Atlantic and Pacific herring provide approximately 700mg of EPA per serving and are among the most omega-3-dense fish available — popular in Scandinavian and Northern European diets.
• Anchovies — Small but mighty — anchovies provide around 400mg EPA per 3.5 oz and are a low-mercury option. Commonly used in Mediterranean cooking and available canned or as paste.

• Fishy breath or burping (most common)
• Loose stools or mild diarrhea at higher doses
• Nausea, especially on an empty stomach
• Mild blood-thinning effect — bruising slightly more easily is possible
• Gastrointestinal discomfort (bloating, reflux)
• Elevated LDL cholesterol reported with very high-dose pure EPA in some studies
• Rare: allergic reaction in people with fish or shellfish allergy (use algae-based EPA instead)

• Recommended daily: General health and inflammation: 1,000–2,000mg EPA/day. Depression or anxiety: 1,000–2,000mg EPA/day (look for supplements where EPA exceeds DHA by at least 2:1). High triglycerides: 2,000–4,000mg EPA/day (prescription-strength may be appropriate). Cardiovascular protection: 4,000mg EPA/day (prescription pure EPA, under medical supervision).
• Best time of day: Any time of day works — morning or evening is fine. Split doses (e.g. morning and evening) can reduce digestive side effects and improve tolerability at higher doses.
• With or without food: Always take with a meal containing fat — this is not optional. EPA absorption roughly doubles when taken with a fat-containing meal compared to a fasted state.
• Time to effect: Triglyceride reduction: 4 weeks. Mood and inflammation improvement: 4–8 weeks. Cardiovascular remodeling and arterial health: 8–12 weeks.
• How long to take it: EPA is typically taken long-term with no need for cycling. Benefits persist with continued use and diminish when stopped. For depression specifically, consider reassessing at 3 months. For cardiovascular and metabolic health, ongoing use is standard.