Dispelling nutrition myths, ranting, and occasionally, raving

Krill oil vs fish oil



I get a lot of questions about omega-3 supplements. Generally these are from fish oil. However, there’s been more interest in the less common krill oil expressed recently.

Krill are tiny little crustaceans. Fish obtain their omega-3s from eating plankton, as do krill. I’d heard that krill oil may be a superior source of omega-3s in comparison to traditional fish oil.

Krill oil actually contains less EPA and DHA (the essential omega-3 fatty acids we aim to obtain from supplements) than fish oils. 1, 000 mg of krill oil generally contains 230-300 mg of omega-3s; 140-160 mg EPA, and 80-90 mg DHA. Compare that to a 1, 000 mg fish oil supplement: 500 mg EPA and 333 mg DHA. However, amounts tend to vary widely between brands and varieties and it’s important to ensure you’re looking at the dose you’ll be taking (many will advise you to take multiple capsules each day which is unnecessary). Advocates for krill oil will tell you that the omega-3s in it are better absorbed than the omega-3s in fish oil. However, there’s not yet any evidence to support this (1).

There may be other benefits to krill oil, such as antioxidant properties. However, as with the previous claim, there is insufficient research to make any claims at this time (2).

One benefit of krill oil that is likely true is that it won’t give you the “fishy burps” that other omega-3 supplements may. If this is a concern to you it’s still avoidable when taking fish oil supplements. Look for supplements that have “enteric coating”. This means that they’ll survive your stomach acid intact and dissolve in your intestine so that they won’t be able to come back to haunt you. You should also take your supplement before your meal, or on an empty stomach, to decrease the transit time.

I had thought that fish oil supplements might be at greater risk of mercury contamination as the fish are considerably larger than the krill. A study showed that fish oil supplements range from no contamination to negligible contamination, rendering that an useless theory.

Other differences between krill oil and fish oil supplements: krill oil tends to be pricier. Also, as krill are crustaceans, krill oil supplements are not safe for sufferers of shellfish allergies.

Bottom line: krill oil may be equally beneficial to fish oil as an omega-3 supplement. It may even have additional benefits. However, the research is not there to support any additional claims. You may want to try krill oil if you’re willing to take a gamble on those additional benefits and if you’re not budget conscious. If you’d rather save your pennies, stick with a high-quality fish oil supplement. And, as always, check with your doctor or pharmacist before taking any supplements, especially if you’re taking any other kind of medication.

Author: Diana

I'm a registered dietitian from Nova Scotia, living and working in Ontario, Canada. My goal is to help people see food and nutrition from a different perspective and understand that nutrition and health are not necessarily a result of personal choice.

2 thoughts on “Krill oil vs fish oil

  1. Thank you for a very thorough and thoughtful summary of how krill and fish oils stack up against each other. As a fish-oil-supplement manufacturer, we’re obviously biased, but it seems clear that while krill is a good product, it’s currently being oversold on rather slender evidence. Fish oil has a half century of solid scientific investigation – much of it independent – and does not make outlandish health claims. Rather, it’s a product that most medical and life sciences authorities have come to recognize bolsters the body’s ability to optimize health and resist a variety of maladies. We invite interested readers to check out additional information on omega 3 and fish oil on our Web site, http://www.Omegafort.com.


  2. Pingback: Of doctors, nutritional nonsense, and tweets | bite my words

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