Fish oil and krill oil both provide omega-3 fatty acids (EPA and DHA). The marketing battle is fierce, but the science is clear: both work, and the "best" choice depends on your priorities and budget.
The Absorption Question
Krill oil's omega-3s are bound to phospholipids, which may absorb better than the triglycerides in most fish oil.
The research: Studies suggest krill oil absorbs about 30% better. But here's the catch: krill oil capsules contain much less EPA/DHA. So you'd need to take more krill oil capsules to match a fish oil dose.
Bottom line: Better absorption doesn't mean better value. Do the math on EPA/DHA per dollar.
Dosing Reality
Therapeutic doses for heart health: 1-2g EPA+DHA daily For inflammation: 2-3g EPA+DHA daily
Fish oil: One 1000mg softgel typically contains 300-500mg EPA+DHA. Take 2-4 daily.
Krill oil: One 500mg softgel typically contains 100-150mg EPA+DHA. You'd need 10+ daily for therapeutic doses.
Most krill oil users take 1-2 capsules daily. This provides modest omega-3s but won't match therapeutic fish oil doses.
The Astaxanthin Bonus
Krill oil contains astaxanthin, a powerful antioxidant that: - Gives krill oil its red color - Helps prevent oxidation - May have independent health benefits
However: The amount in krill oil (0.5-1mg per capsule) is lower than standalone astaxanthin supplements (4-12mg). If you want astaxanthin specifically, supplement it separately.
Quality Matters More Than Type
A high-quality fish oil beats a low-quality krill oil, and vice versa.
For fish oil: - Choose triglyceride form over ethyl ester - Look for third-party testing (IFOS certification) - Check for freshness (no strong fishy smell)
For krill oil: - Antarctic krill (Euphausia superba) is standard - MSC certified for sustainability - Phospholipid content should be listed
The Bottom Line
Fish oil is the practical choice for most people. It's affordable, well-researched, and easy to dose therapeutically. Krill oil is fine if you prefer smaller pills, want the astaxanthin, and don't mind paying more for less EPA/DHA.