Skip to main content
Lab bench in soft warm light
The ruleNo winner, no loser. Both have an audience.
Which fits which goal

Fish Oil vs Krill Oil: The Omega-3 Comparison

The short read

Fish oil delivers far more EPA/DHA per serving, which is what a therapeutic dose is made of. Krill oil absorbs roughly 30% better and carries astaxanthin, but each capsule holds a fraction of the omega-3s. Dose target decides: reaching 1-2g EPA+DHA is straightforward with fish oil and takes many capsules of krill.

FitsMost people, and anyone dosing to a therapeutic EPA/DHA target
Where it is strongerMore EPA/DHA per servingDecades of researchEasier to get therapeutic dosesMany quality options
Where it gives groundFish burps possibleLarger softgelsTriglyceride form varies by brandMay oxidize if poor quality
FitsThose who can't tolerate fish oil or want the astaxanthin alongside
Where it is strongerPhospholipid form (better absorption)Contains astaxanthin (antioxidant)Smaller softgelsLess fishy aftertasteMore stable (less oxidation)
Where it gives groundLower EPA/DHA per capsuleNeed more capsules for therapeutic doseShellfish allergy risk
Side by side
Fish OilKrill Oil
EPA+DHA per serving500-1000mg typical100-300mg typical
AbsorptionGood (triglyceride form)Higher (phospholipid form)
Fish burpsPossibleRare
Additional benefitsNoneAstaxanthin antioxidant
Research depthExtensively studiedStudied
SustainabilityVaries by sourceGenerally sustainable
Fish Oil fitsMost people, and anyone dosing to a therapeutic EPA/DHA target
Krill Oil fitsThose who can't tolerate fish oil or want the astaxanthin alongside

Fish oil and krill oil both provide omega-3 fatty acids (EPA and DHA). The marketing battle is fierce, but the science is calmer: both work, and the delivered dose is what separates them in practice.

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 several krill capsules to match one fish oil softgel.

Bottom line: Absorption doesn't offset dose. Compare the delivered EPA/DHA, not the label promises.

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

Sourcing, form and freshness separate products more than the fish-vs-krill choice does.

For fish oil: - Check the label for triglyceride vs ethyl ester form; absorption data differs between them - 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 route to a therapeutic EPA/DHA dose and carries the deeper research base. Krill oil suits smaller pills, gentler digestion and the astaxanthin bonus, at a much lower omega-3 dose per capsule.

More comparisons

Educational reading, not medical advice. Your doctor makes the call for your body.

Written and reviewed by the IngredientMD editorial team.