Due to limited research, the side effects of krill oil are not well documented and limited information is available. In some cases krill oil may cause gastrointestinal disturbance with symptoms of:
Krill oil may have blood thinning properties so should not be taken alongside drug thinning drugs such as warfarin. Due to possible interactions with other drugs a person should seek advice from a physician first if they are currently taking medication.
As krill are shrimp like marine based creatures (see also, 'what are krill?'), krill oil should not be used by people allergic to seafood.
As with many foods and forms of health supplements, the FDA of the United States has not set a recommended dosage for krill oil.
However, the FDA have set a recommended daily dose for omega-3 EPA and DHA fatty acids which krill oil is rich in.
The FDA advise that up to 2 grams of EPA and DHA omega-3 fatty acids be taken from supplements each day. Overall up to 3 grams can be consumed if the rest is sourced from omega-3 rich foods like oily cold water fish.
As a guide to dosage , the following list is the dosage advised by popular krill oil supplements.