The krill oil from at least one manufacturer has been found Generally Regarded As Safe (GRAS) by the Food and Drug Administration (FDA). This determination is an indication that taking krill oil is very safe.
Krill oil, like fish oil, has blood-thinning properties, as mentioned under the Krill Oil Benefits section, so it is not advised for anyone who is taking a prescription blood-thinner such as Warfarin (Coumadin), or high-dose aspirin, without first consulting his or her physician.
Krill is a marine creature, so if you have an allergy to seafood, you will want to proceed with caution. However, the allergy is caused by the krill proteins and pure krill oil should not contain any of these proteins. It’s therefore highly unlikely that anyone would have an allergic reaction from taking krill oil. Nevertheless, if you already know that you have this shellfish allergy, then you must follow your doctor’s advice.
Also, krill oil suppliers recommend consulting a physician before taking krill oil if you are pregnant or breastfeeding.
It is important to note that there have been no reports of serious adverse events from taking krill oil.
More about krill oil side effects:
WellWise has two more important pages about the side effects of krill oil.