Krill Oil vs Fish Oil

Krill oil and fish oil both supply EPA and DHA, and they are compared on capsule count more often than they should be. The two differ in the chemical form the omega-3 arrives in, in typical dose per capsule, and in price.

Phospholipid versus triglyceride form

In krill oil the omega-3 fatty acids are largely bound in phospholipid form; in fish oil they are predominantly in triglyceride or ethyl ester form. This is the substantive difference between the two and the basis of most krill marketing.

Dose per capsule is usually lower

Krill oil capsules typically carry less EPA and DHA per capsule than concentrated fish oil. That does not make them worse, but it does mean a bottle-to-bottle or capsule-to-capsule comparison is not meaningful. Convert both to EPA plus DHA per serving — see EPA and DHA explained.

Astaxanthin

Krill oil naturally contains astaxanthin, which gives it its red colour and is usually stated on the label. It is specific to krill among these products.

Allergy

Krill is a crustacean. Anyone with a shellfish allergy should avoid krill oil. This is stated on labels as an allergen declaration and it is the most important practical difference between the two categories.

Sustainability

Sourcing certification appears on products in both categories. Where a manufacturer states a certification, we record it as their claim.

Price

Krill oil is generally more expensive per unit of EPA and DHA. Whether the phospholipid form justifies that is exactly the sort of question where the honest answer is that the research is ongoing rather than settled, and where a retailer telling you confidently either way is overstating what exists.

Compare directly

Our krill oil and fish oil comparisons filter by brand, strength and pack size. For plant-source options see omega-3.

References

• NIH Office of Dietary Supplements — Omega-3 Fatty Acids (Health Professional Fact Sheet)
• NCCIH — Omega-3 Supplements: In Depth