Krill Oil vs Fish Oil: An Honest Comparison from a Krill Oil Maker

We make krill oil. We’ve been making it for twenty years on a boat in Antarctic waters. So when people ask us whether krill oil is better than fish oil, we have an obvious bias — and we’re going to share as straight as we can.

The Short Answer

Krill oil and fish oil both deliver omega-3 fatty acids (EPA and DHA) that support heart health, joint comfort, and brain function. Fish oil gives you more EPA and DHA per capsule and costs less. Krill oil may be absorbed more efficiently and comes with astaxanthin, a natural antioxidant. Neither is “wrong” — the right choice depends on what matters most to you.

What They Have in Common

Both krill oil and fish oil provide the same two omega-3 fatty acids your body needs: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These are the omega-3s that decades of research have linked to cardiovascular health, joint comfort, cognitive function, and healthy inflammatory response. Whether you get them from krill or fish, your body uses them the same way.

Where They Differ: The Phospholipid Question

This is the big one, and it’s real — not marketing.

In fish oil, omega-3s are bound to triglycerides. In krill oil, a significant portion of the omega-3s are bound to phospholipids. Why does that matter? Because your cell membranes are made of phospholipids. The theory — supported by several studies — is that phospholipid-bound omega-3s integrate into cell membranes more efficiently.

A 2015 study published in Lipids in Health and Disease found that over 72 hours, blood concentrations of EPA and DHA were higher in participants who took krill oil compared to those who took fish oil, even though the krill oil capsule contained fewer total omega-3s. (Ramprasath et al., 2015)

However, a 2023 meta-analysis of 14 randomized controlled trials showed that fish oil supplementation resulted in greater overall improvements in heart health markers compared to krill oil. The research is genuinely mixed. We’re not going to pretend it isn’t.

EPA and DHA Content: Fish Oil Wins on Paper

A typical fish oil softgel delivers 360 mg EPA and 240 mg DHA — about 600 mg combined omega-3s per capsule. A typical krill oil softgel delivers 60–150 mg EPA and 30–90 mg DHA — significantly less per capsule.

If you’re comparing milligrams per dollar, fish oil wins every time. That’s a fact. The counterargument from the krill oil side is that the phospholipid form may require less total EPA/DHA to achieve the same blood levels. The research supports this to some degree, but it’s not settled enough for us to claim equivalence.

Astaxanthin: The Bonus in Krill Oil

Krill oil naturally contains astaxanthin, a carotenoid pigment that gives krill (and salmon, and flamingos) their reddish color. Astaxanthin is one of the most potent natural antioxidants studied, with research suggesting it may support eye health, skin health, and exercise recovery.

Fish oil doesn’t contain astaxanthin. Some fish oil brands add it separately, but it’s not naturally occurring in the product.

The Burp Factor

Let’s talk about something the clinical studies don’t measure: fishy burps. Fish oil reflux is the #1 reason people stop taking omega-3 supplements. Krill oil is significantly less likely to cause this because phospholipids mix with stomach contents more readily than triglycerides, reducing the “fish oil repeat” that plagues fish oil users.

This isn’t a minor quality-of-life point. The best omega-3 supplement is the one you actually take every day. If fishy burps make you skip doses, a supplement with higher per-capsule EPA/DHA doesn’t help you.

Extraction: Where Captains Is Different

Most omega-3 supplements — both fish oil and krill oil — are extracted using chemical solvents (typically hexane). The solvents are removed during processing, but the process itself strips some of the natural compounds from the oil.

Captains Krill Oil uses mechanical extraction directly on the boat. No chemical solvents. No factory processing. No warehousing between catch and extraction. The krill goes from ocean to oil in hours, not weeks. This preserves more of the natural phospholipid structure and astaxanthin content.

We’re one of very few krill oil brands that can say this. Most krill oil on the market — including brands that cost more than ours — use conventional solvent extraction in a factory far from the ocean.

Cost: Be Honest About the Price

Krill oil costs more than fish oil. Period. Harvesting krill in Antarctic waters is expensive. Small-batch mechanical extraction is more expensive than industrial chemical extraction. A month’s supply of quality krill oil runs $40–60 compared to $10–20 for quality fish oil.

If budget is your primary constraint, fish oil from a reputable brand (look for third-party testing and IFOS certification) is a perfectly good choice. We’d rather you take fish oil every day than skip krill oil because you can’t afford it.

Sustainability

Antarctic krill (Euphausia superba) is one of the most abundant animal species on Earth, with an estimated biomass of 300–500 million tonnes. The krill fishery is managed by CCAMLR (Commission for the Conservation of Antarctic Marine Living Resources) and current harvest levels are well below 1% of estimated biomass.

Fish oil sustainability varies enormously by species and source. Some fisheries are well-managed; others are severely overfished. If sustainability matters to you, look for MSC certification on fish oil or CCAMLR-regulated sourcing on krill oil.

Side-by-Side Comparison

So Which Should You Choose?

Choose fish oil if: Budget is your top priority, you want maximum EPA/DHA per capsule, you don’t mind taking 3–6 capsules daily, and fishy aftertaste doesn’t bother you.

Choose krill oil if: You value absorption efficiency over raw milligrams, you want the added antioxidant benefit of astaxanthin, fishy burps have made you quit fish oil before, and you’re willing to pay more for a product you’ll actually take consistently.

Choose Captains Krill Oil specifically if: You want the krill oil advantages above, plus mechanical extraction with no chemical solvents, boat-to-bottle processing within hours of harvest, and a 20-year track record from a company that makes one product and makes it right.

This page is for informational purposes only and is not intended as medical advice. Consult your healthcare provider before starting any supplement regimen. Individual results may vary.

References

Ramprasath, V.R. et al. (2015). “Supplementation of krill oil with high phospholipid content increases sum of EPA and DHA in erythrocytes compared with low phospholipid krill oil.” Lipids in Health and Disease, 14, 142. PMC4559234

Ulven, S.M. et al. (2011). “Metabolic effects of krill oil are essentially similar to those of fish oil but at lower dose of EPA and DHA, in healthy volunteers.” Lipids, 46(1), 37–46.

Cicero, A.F.G. et al. (2023). Meta-analysis of 14 randomized controlled trials comparing krill oil and fish oil cardiovascular outcomes.