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.

Background

• 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.

Scientific Evidence

Tradition/Theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

• Abnormal heart rhythms, acute respiratory distress syndrome (ARDS), age-related macular degeneration (deteriorating central retina cells), aggressive behavior, aging, agoraphobia (situational anxiety), AIDS, allergies, anthracycline-induced cardiac toxicity (heart damage from anthracycline use), antioxidant, antiphospholipid syndrome (increased blood clotting tendency), appetite suppressant, asthma, attention-deficit hyperactivity disorder (ADHD), autoimmune disorders (nephritis), bacterial infections, blood thinner, bone diseases, breast pain, breast cancer, breast cysts, breast tenderness, cancer, carpal tunnel syndrome (compressed hand or wrist nerves), chronic fatigue syndrome, chronic obstructive lung disease (lung disease from narrowed airways), circulatory disorders, cirrhosis (chronic liver disease), cognitive function, common cold, concentration enhancement, congestive heart failure, critical illness, dementia, depression, dermatomyositis (skin and tissue inflammation), diabetes, diabetic nephropathy (diabetes-related kidney disease), diabetic neuropathy (diabetes-related nerve damage), digestive disorders, dry eyes, dyslexia (disordered reading ability), dyspraxia (disordered motor coordination), ear infection, energy, exercise performance enhancement, fatigue, fibromyalgia (chronic muscle pain and weakness), gallstones, gingivitis (inflamed gums), glaucoma (increased pressure within the eye), gout, H. pylori infection, hay fever, headache, hearing loss (age-related), heart attack, heart disease, hepatorenal syndrome (combined kidney impairment and liver disease), high blood pressure, hormonal disorders, hyperglycemia (high blood sugar levels), hypoxia (lack of oxygen), ichthyosis (dry and scaly skin), immune disorders (Behçet's syndrome), immune suppression, inflammation, joint pain, joint problems (cartilage destruction), kidney disease prevention, kidney inflammation, kidney problems, kidney stones, leprosy, leukemia (blood cell cancer), malaria, male infertility, memory enhancement, memory loss, menopausal symptoms, menstrual cramps, metabolic disorders (glycogen storage diseases), methotrexate toxicity, mood, multiple sclerosis (loss of nerve insulation and function), myopathy (muscle disease), neurologic disorders (Refsum's syndrome), neuropathy (nerve damage), neuroprotection (nerve protection), night vision enhancement, nutrition supplementation (omega-3 fatty acid), osteoarthritis (cartilage loss), osteoporosis (bone loss), panic disorder, paranoid personality disorder, peripheral vascular disease (non-heart-associated blood vessel disease), postpartum depression (maternal depression after childbirth), postviral/chronic fatigue syndrome, pregnancy nutritional supplement, premature birth prevention, premenstrual syndrome, prostate cancer prevention, protection from isotretinoin drug toxicity, Raynaud's phenomenon (lowered circulation causing discolored extremities), Reye's syndrome (liver and brain swelling), rheumatoid arthritis (chronic joint inflammation), seizure disorder, skin cancer, stress, stroke, sunburn prevention, systemic lupus erythematosus (connective tissue inflammation), tardive dyskinesia (involuntary body movements), tennis elbow (elbow tendon inflammation), urinary stones, vision enhancement, vision problems (age-related), weight loss, well-being, wound healing.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

• Krill oil is distributed by Neptune Technologies & Bioressources, Inc. Each 500-milligram capsule of Neptune Krill Oil™ contains 50 international units (IU) of vitamin A, 0.25 IU of vitamin E, 150 milligrams of omega-3 fatty acids, 75 milligrams of eicosapentaenoic acid (EPA), 45 milligrams of docosahexaenoic acid (DHA), 10 milligrams of omega-6 fatty acids, 42.5 milligrams of omega-9 fatty acids, 200 milligrams of phospholipids, and 0.75 milligrams of astaxanthin.

• For arthritis, 300 milligrams of Neptune Krill Oil™ has been taken daily for 30 days.

• For dental plaque or gingivitis, 0.06 units of Krillase® gum has been chewed by mouth for 10 minutes after meals, four times daily for 10 days.

• For high blood lipids, 1-3 grams of Neptune Krill Oil™ has been taken daily for up to three months. Six capsules (500 milligram capsules each) of krill oil has also been taken daily for seven weeks.

• For painful menstruation, two grams of Neptune Krill Oil™ has been taken daily for up to three months.

Children (under 18 years old)

• There is no proven safe or effective dose for krill oil in children.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

• Avoid in people with a known allergy or sensitivity to seafood or shellfish.

• Antarctic krill has been shown to contain tropomyosins. Tropomyosins are compounds known to induce a major allergic reaction upon binding with shrimp-related immune molecules.

Side Effects and Warnings

• Neptune Krill Oil™ (Neptune Technologies & Bioressources Inc.) is likely safe when taken in recommended doses for up to three months.

• Side effects of krill may include bad breath, bloating, diarrhea, "fishy" tasting burps, flatulence, general itchiness, hand swelling, or oily facial skin.

• Krill may increase the risk of bleeding. Caution is advised in people with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.

• Krill oil may lower blood sugar levels. Caution is advised in people with diabetes or hypoglycemia and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

• Krill oil may cause low blood pressure. Caution is advised in people taking agents that lower blood pressure.

• Avoid with known allergy or sensitivity to seafood or shellfish.

Pregnancy and Breastfeeding

• There is currently a lack of scientific evidence on the use of krill during pregnancy or lactation.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

• Krill oil may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

• Krill oil may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. People taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

• Krill may cause low blood pressure. Caution is advised when using medications that may also lower blood pressure.

• Krill may also interact with agents that affect the heart and blood vessels, agents toxic to the liver, anticancer agents, anti-inflammatory agents, bone loss agents, hormonal agents, kidney-protective agents, lipid-lowering agents, nervous system agents, and pain relievers.

Interactions with Herbs and Dietary Supplements

• Krill oil may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.

• Krill oil may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

• Krill oil may cause low blood pressure. Caution is advised in people taking herbs or supplements that lower blood pressure.

• Krill may also interact with herbs and supplements that affect the heart and blood vessels, anticancer herbs and supplements, anti-inflammatories, antioxidants, bone loss herbs and supplements, herbs and supplements toxic to the liver, hormonal herbs and supplements, kidney-protective herbs and supplements, lipid-lowering agents, nervous system herbs and supplements, pain relievers, and vitamin A.

Author Information

• This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

1. Banni S, Carta G, Murru E, et al. Krill oil significantly decreases 2-arachidonoylglycerol plasma levels in obese subjects. Nutr Metab (Lond) 2011;8(1):7. View Abstract

2. Bridges KM, Gigliotti JC, Altman S, et al. Determination of digestibility, tissue deposition, and metabolism of the omega-3 fatty acid content of krill protein concentrate in growing rats. J Agric.Food Chem 2010;58(5):2830-2837. View Abstract

3. Bunea R, El Farrah K, Deutsch L. Evaluation of the effects of Neptune Krill Oil on the clinical course of hyperlipidemia. Altern Med Rev 2004;9(4):420-428. View Abstract

4. Deutsch L. Evaluation of the effect of Neptune Krill Oil on chronic inflammation and arthritic symptoms. J Am Coll Nutr 2007;26(1):39-48. View Abstract

5. Gigliotti JC, Smith AL, Jaczynski J, et al. Consumption of krill protein concentrate prevents early renal injury and nephrocalcinosis in female sprague-dawley rats. Urol Res 2011;39(1):59-67. View Abstract

6. Lee B, Sur BJ, Han JJ, et al. Krill phosphatidylserine improves learning and memory in Morris water maze in aged rats. Prog Neuropsychopharmacol Biol Psychiatry 2010;34(6):1085-1093. View Abstract

7. Maki KC, Reeves MS, Farmer M, et al. Krill oil supplementation increases plasma concentrations of eicosapentaenoic and docosahexaenoic acids in overweight and obese men and women. Nutr Res 2009;29(9):609-615. View Abstract

8. Hellgren K. Assessment of Krillase chewing gum for the reduction of gingivitis and dental plaque. J Clin Dent 2009;20(3):99-102. View Abstract

9. Ierna M, Kerr A, Scales H, et al. Supplementation of diet with krill oil protects against experimental rheumatoid arthritis. BMC Musculoskelet Disord 2010;11:136. View Abstract

10. Sampalis F, Bunea R, Pelland MF, et al. Evaluation of the effects of Neptune Krill Oil on the management of premenstrual syndrome and dysmenorrhea. Altern Med Rev 2003;8(2):171-179. View Abstract

11. Schuchardt JP, Schneider I, Meyer H, et al. Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations-a comparative bioavailability study of fish oil vs. krill oil. Lipids Health Dis 2011;10:145. View Abstract

12. Tandy S, Chung RW, Wat E, et al. Dietary krill oil supplementation reduces hepatic steatosis, glycemia, and hypercholesterolemia in high-fat-fed mice. J Agric Food Chem 2009;57(19):9339-9345. View Abstract

13. Tou JC, Jaczynski J, Chen YC. Krill for human consumption: nutritional value and potential health benefits. Nutr Rev 2007;65(2):63-77. View Abstract

14. Ulven SM, Kirkhus B, Lamglait A, et al. Metabolic effects of krill oil are essentially similar to those of fish oil but at lower dose of EPA and DHA, in healthy volunteers. Lipids 2011;46(1):37-46. View Abstract

15. Zhu JJ, Shi JH, Qian WB, et al. Effects of krill oil on serum lipids of hyperlipidemic rats and human SW480 cells. Lipids Health Dis 2008;7:30. View Abstract