Krill oil

Also known as krill.

Last reviewed October 9, 2026 · Jump to references

What is Krill oil?

In plain words

Krill oil comes from small ocean animals related to shrimp and contains omega-3 fats. The body digests these fats and uses them in cell membranes and chemical signals. Researchers study it for effects on blood fats, heart health, and joint symptoms, but evidence for clear health benefits remains limited. It can cause stomach upset and may pose an allergy risk for people allergic to shellfish.

Technical definition

Krill oil is a marine lipid extract from small crustaceans, typically Antarctic krill (Euphausia superba), containing the omega-3 fatty acids EPA and DHA, largely associated with phospholipids, along with the carotenoid astaxanthin. Following digestion and absorption, EPA and DHA enter cell membranes and influence lipid signaling and inflammatory mediator production rather than acting through one specific receptor. In the United States, krill oil is marketed as a dietary supplement and is not FDA-approved to treat disease.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.