What is Krill Oil?

Krill are tiny, shrimp-like crustaceans that flourish in the Antarctic Ocean and provide food for numerous aquatic animals. Oil made from krill has come on the market as an alternative to fish oil . Like fish oil, krill oil contains the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Krill also contains omega-6 fatty acids , an antioxidant in the carotenoid family called astaxanthin , and substances called phospholipids.

Based on its omega-3 fatty acid content, krill oil would be expected to have many of the same effects as fish oil. See the full Fish Oil article for a detailed discussion of these potential benefits.

A few studies have evaluated krill oil specifically. In one double-blind , placebo-controlled study, 120 people with high cholesterol were given krill oil, fish oil, or placebo. ¹ The results over 3 months showed that krill oil (taken at a dose ranging from 1-3 g daily depending on body mass and which group the participants were assigned to) improved all aspects of cholesterol profile as compared to placebo, and it was more effective than fish oil (taken at the fixed dose of 3 g daily). Krill oil also reduced blood sugar levels. Though these results need to be confirmed by...

Safety Issues

Based on its known constituents, krill oil would be expected to have little to no toxicity. Side effects seen in studies are limited to occasional digestive distress and allergic reactions. The only known potential concerns relate to possible blood-thinning effects: Fish oil is known to decrease blood coagulation, and in one case report it increased the effect of the blood-thinning medication warfarin (Coumadin). ² People who are at risk of bleeding complications for any reason should consult a physician before taking krill oil. Maximum safe doses in young children, pregnant or nursing women, or people with severe liver disease have not been established.