Krill Oil Side Effects, Important Info, How to Take & More

Krill oil is oil extracted from small, shrimp-like sea animals known as Euphausia Superba. The whole “krill” in Norwegian means “Whale food” because whales, mantas and sharks alike feast on these tiny animals.


The oil extracted from these animals is encapsulated and high in demand for its benefits in treatment for heart diseases, elevated blood fats levels (triglycerides) and high levels of cholesterol. However, there is limited research to back up these claims.

Side Effects:

People who experience allergic reactions to seafood may also be hypersensitive to krill oil. There is not enough evidence to determine how much people are allergic to seafood to show allergic reactions to krill oil. It is advisable to use krill oil cautiously if you are allergic to seafood.

There are numerous proved and unproved side effects of krill oil use:

  • Fever, chills, body aches, flu symptoms
  • Chest pain
  • Uneven heartbeats
  • Back pain
  • Mild skin rash
  • Fishy aftertaste or belching in some patients



There more severe side effects observed in people suffering from other diseases:

  • Blood-thinning
    • It is a serious risk as due to slow blood clotting a person is more prone to developing bleeding disorders.
  • Diabetes:
    • Krill oil has the tendency to lower the blood glucose level and cause diabetics to go into hypoglycemia
  • Obesity
    • Krill oil might compromise the effectiveness of insulin in the body of an already obese or overweight individual.
    • Additionally, it can increase the risk of developing diabetes and heart diseases.
  • Surgery:
    • Due to slower blood clotting and blood thinning abilities of the oil, it is advised to cease the use of krill oil at least 2 weeks prior to scheduled surgery to prevent bleeding out during the process.

Krill oil can oxidize and spoil during the capsulation process leading to the risk of potential health hazards.

How to use:

Use krill oil as directed by the doctor and don’t take larger or smaller doses than prescribed as that could have a negative impact on your health.

Take the capsule in your mouth and swallow it whole without puncturing or chewing on it. It works better when taken with a meal, but it can be taken without a meal as well.

The appropriate dose of krill oil is dependent upon the user’s age, weight, diet, medical history, etc.



Krill oil is the most effective when used in combination with a healthy diet, routine exercise and managed weight.

In case you miss a dose, take it as soon as you realize your mistake. If it is, however, time for the next dose, then skip the one missed. Taking the current dose and missed both at once could lead to poisoning and multiple other health-related issues.

Avoid eating foods high in fat and cholesterol and abstain from consuming alcoholic beverages as they are high in triglycerides.



Make sure to tell your doctor about your medical history before using this medicine especially if you have:

  • Liver disease
  • Diabetes
  • Underactive thyroid
  • Blood clotting and risk of stroke
  • Have an upcoming surgery which may involve bleeding risks
  • Drink more than 2 glasses of alcoholic beverages in a day



It is still unknown whether the use of krill oil has adverse effects during pregnancy and on the fetus or whether it passes to the baby via breast milk. Therefore, it is recommended not to breastfeed while taking krill oil.

Furthermore, using krill oil while also using blood thinning medication can lead to numerous severe and possibly fatal consequences. It is recommended to tell your doctor about all medicines you are currently administering before using krill oil.