Krill is a spineless, shrimp-like marine organism. The oil produced from krill, in particular from Antarctic krill (Euphausia superba), is rich in various compounds, including long-chain omega-3 fatty acids and antioxidants, which likely contribute to krill oil's beneficial health effects.
An estimated 14% of krill oil is comprised of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are both omega-3 fatty acids. Omega-3 fatty acids are a class of compounds believed to have beneficial blood lipid- and blood pressure-lowering effects. Krill oil is also believed to contain astaxanthin. Astaxanthin is an antioxidant with purported neuroprotective effects.
Early research suggests that krill oil may be useful in the treatment of arthritis, high blood lipids, dental plaque, and painful menstruation. However, further research in these areas is needed before any firm conclusions may be made for its use.

Related Terms

Antarctic krill, Antarctic krill oil, Antarctic krill peptide powder (AKPP), Antarctic krill tail meat hydrolysate, Arctic Wonder Krill Oil, arthropod, astaxanthin, crustacean, DHA, dietary (n-3) LCPUFA, dietary (n-3) long-chain PUFA, docosahexaenoic acid, eicosapentaenoic acid, EPA, Euphausia pacifica, Euphausia superba, Euphasia superba Dana, Euphausia superba oil, Euphausiacea, euphausiid, euphausiids oil, krill oil complex, krill omega-3 oil, krill protein concentrate (KPC), Krillase® chewing gum, Malacostraca, marine ectotherm, marine protein concentrate, Meganyctiphanes, Meganyctiphanes norvegica Sars, MegaRed Omega-3 Krill Oil, MURST-ISS-A2, n-3 fatty acids, Neptune Krill Aquatein (NKA™), Neptune Krill Oil™ (NKO™), Neptune Ocean Extract (NOE™), NKO™, North Pacific krill, northern krill, omega 3, omega-3, omega-3 fatty acids, omega-3 oil, omega-3 polyunsaturated fatty acids, omega-3 PUFAs, Pacific krill, pelagic Antarctic species, pelagic crustacean, phosphatidylcholine, phospholipid, polyunsaturated fatty acids, shellfish, Thysanoessa, water-soluble extract of Pacific krill, zooplankton.
Note: Krill is a source of omega-3 fatty acids. The majority of krill's purported benefits are likely due to its constituent omega-3 fatty acids. However, this summary focuses on krill itself, rather than on the effects of omega-3 fatty acids in general.

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Alzheimer's disease (Grade: C)
Results are pending on preliminary research exploring the effects of krill oil in people with early-stage Alzheimer's disease. Until more research becomes available, firm conclusions about the use of krill oil in this area are lacking.
Arthritis (chronic inflammation) (Grade: C)
Limited research suggests that krill oil may lower arthritis pain and markers of inflammation. However, more large-scale, high-quality research is needed in this area.
Dental plaque/gingivitis (Grade: C)
According to early research, Krillase® chewing gum has been shown to reduce dental plaque and inflammation-related gum bleeding. Additional research in this area is needed before any firm conclusions may be made.
Lipid lowering effects (Grade: C)
Limited research suggests that, compared to fish oil, krill oil reduces the level of various blood lipids, including total cholesterol and low-density lipoprotein (LDL) cholesterol, and the ratio of total cholesterol to high-density lipoprotein (HDL) cholesterol. Although this is promising, further research in this area is needed before any firm conclusions may be made.
Painful menstruation (Grade: C)
Limited research suggests that krill oil may mitigate both physical and emotional symptoms of painful menstruation. However, more large-scale, high-quality research is needed in this area.