Fish oil is among the most popular supplements but evidence is mixed for several common uses. Is fish oil worth taking depends on what you’re trying to address. Higher EPA preparations have stronger cardiovascular evidence; general low-dose supplementation has weaker support.
What evidence supports
High triglycerides: Effective at high doses (3-4 g EPA+DHA daily). Prescription icosapent ethyl (Vascepa) FDA-approved.
Cardiovascular events: REDUCE-IT trial showed icosapent ethyl reduced events. Mixed evidence for OTC fish oil.
Inflammatory conditions: Some evidence for rheumatoid arthritis.
Pregnancy: DHA important for fetal brain development.
Mood (depression): Higher EPA preparations show some benefit.
Where evidence is weaker
- General cardiovascular prevention with low-dose OTC fish oil
- Cognitive function in healthy adults
- Skin health
- Most “general health” claims
Quality considerations
- Look for IFOS-certified products (third-party tested)
- Mercury and PCB content matters
- Triglyceride form may absorb better than ethyl ester
- Capsule potency varies dramatically
Algae oil alternatives
Plant-based DHA (sometimes EPA) from algae:
- Vegan-friendly
- No fish/contamination concerns
- Generally lower potency per cost
- Acceptable alternative
Frequently Asked Questions
How much fish oil should I take?
For general use, 1-2 g EPA+DHA daily. For triglyceride lowering, 3-4 g.
Is fish oil better than eating fish?
Eating fatty fish (salmon, sardines, mackerel) 2x/week is the standard recommendation. Supplements supplement.
Does fish oil cause bleeding?
High doses theoretically. Discuss before surgery.
Is icosapent ethyl better?
Pure EPA, prescription. Strong cardiovascular evidence at high doses.
What about krill oil?
Comparable benefits at lower doses; more expensive per gram of omega-3.
The bottom line on fish oil
Worth taking for high triglycerides, inflammatory conditions, pregnancy. Weaker evidence for general cardiovascular prevention. Look for certified products.