Does Krill Oil Cause Side Effects?

No significant adverse side effects including reflux have been reported in various studies of Neptune Krill Oil (NKO™). (Always look for the NKO trademark on any private-labeled krill oil bottle.) Further, NKO™ is approved as safe for human consumption by the U.S. Food and Drug Administration. However, people with seafood allergies should not take krill oil.

The FDA's recent review of the safety of omega 3 fatty acids concluded that up to 3 grams EPA and DHA daily is generally recognized as safe. Dosages up to 8 grams of omega 3 fatty acids per day have shown no significant adverse effects.

Long-term krill oil safety studies on mice yielded no adverse effects from the human equivalent of 9 grams of NKO™ EPA and DHA daily for 6 months (equal to 27 human years). Examination of brain, heart, lungs, stomach, intestines, pancreas, liver, kidneys, uterus/prostate and skin yielded no pathological findings.

NKO™ is completely free of mercury, heavy metals, PCBs, dioxins and other contaminants found in fish and shellfish because the krill is at the bottom of the food chain and does not accumulate the pollutants affecting other marine life. Further, NKO™ is harvested only from clean Antarctic waters.

The results of a toxicity study confirmed that NKO™ can be considered safe for human consumption even at 2 to 3 times the highest recommended dose.

Maximum safe doses for pregnant or nursing women, people with severe liver disease, and young children have not been established.


As mentioned, if you are allergic to seafood, do not take krill oil. Krill oil may decrease blood coagulation and may increase the effect of the blood-thinning medication wafarin. Therefore, people taking wafarin or any anticoagulent and people at risk of bleeding complications for any reason should consult a physician before taking krill oil. Krill oil should be discontinued prior to surgery. Women who are pregnant, breast-feeding or plan to be should consult a physician before taking krill oil.

1Statements on this website have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Precautions: If you are pregnant, nursing, allergic to fish or shellfish, have a blood coagulation condition, are taking anticoagulants such as warfarin, or are currently under a physician's care for a health condition, please consult a healthcare professional prior to use.

NKO™ is a trademark of its manufacturer, Neptune Technologies and Bioresources, Inc.