Krill Oil vs Fish Oil: What is the Difference?

Are krill oil and fish oil the same?

Which one should you take?

What are the benefits of these supplements?

I receive a lot of questions regarding the differences between krill oil and fish oil.  I decided to answer this question and explore the benefits of these supplements.  Let’s start with the basics.

The traditional fish oil supplements are derived from fatty fish such as salmon, anchovies, tuna, herring, sardines, and mackerel.  Fish oil is one of the most popular dietary supplements consumed world-wide.

Krill oil comes from Antarctic krill, which are tiny crustaceans.  Krill is consumed by other sea animals such as penguins, whales, seals, and birds.

Krill Oil and Fish Oil Both Contain Omega-3 Fatty Acids

Omega-3 fatty acids are necessary for proper brain and nerve function.  They are an essential component of the membrane that surrounds each of our cells.  Omega-3’s are known as essential fatty acids because they must be obtained from food sources as our bodies cannot produce them.1

 Krill oil and fish oil both contain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).  These are omega-3 fatty acids that have the ability to improve brain health and heart health.   The difference is how fatty acids are stored.  It appears that krill oil stores omega-3’s as phospholipids, whereas fish oil stores them as fatty acids.

This may be an important factor in how our body utilizes them.  There have been some small studies comparing Fish oil and krill oil.  One study published in 2015 found a higher plasma concentration of EPA and DHA in subjects receiving krill oil compared to those who ingested fish oil supplements.2

Omega-3 supplements have the following benefits:

  • Decreasing high triglyceride levels – When your triglyceride levels are too high, the risk of atherosclerosis and heart disease increases.
  • Treatment of rheumatoid arthritis – Some evidence suggests Omega-3 fatty acids may help with the treatment of rheumatoid arthritis. One study published in 2017 concluded that “higher intake of vitamin D and omega-3 fatty acids during the year preceding disease-modifying antirheumatic drugs may be associated with better treatment results in patients with early rheumatoid arthritis.”3

Krill Oil Contains Astaxanthin

Astaxanthin is a carotenoid pigment that has many health benefits of its own. This substance gives krill oil its reddish color and is not found in most fish oil supplements.

Astaxanthin acts as an antioxidant and anti-inflammatory and may promote cardiac health.4

Krill Oil May Be More Effective in Treating Hyperlipidemia

A multi-center randomized, controlled study found krill oil to be significantly more effective than fish oil in reducing glucose, triglyceride, and LDL levels.5 

Krill oil was also able to significantly lower total cholesterol and increase HDL levels in this study.  

Other Sources of Omega-3s

Omega-3 fatty acids naturally occur in some foods and are artificially added to others.  Some examples include:6

  • Fish and seafood (especially salmon, herring, sardines, mackerel, and tuna).
  • Plant oils (flaxseed, soybean, and canola).
  • Nuts and seeds (Chia seeds, walnuts, flaxseed).
  • Fortified foods (some eggs, yogurt, milk, juice, and soy beverages).

Other sources include cod liver oil and algal oil.  Algal oil is derived from algae and is a great choice for vegans and vegetarians.

Is Fish Oil Easier to Obtain?

Fish oil supplements can be found in most grocery stores.  Krill oil is becoming more popular, and with the ability to order supplements over the internet, it is certainly not difficult to obtain.  Fish oil may be cheaper than krill oil, but our omega-3 and krill oil supplements are similarly priced. 

Side Effects of Krill Oil and Fish Oil

The side effects of krill oil and fish oil are similar and very mild.  These include:

  • Diarrhea
  • Headache
  • Upset stomach and heartburn
  • Bad breath
  • Fishy smelling sweat
  • Acne and oily skin
  • Nausea
  • Flatulence
  • Fishy burps

Drug Interactions

Both fish oil supplements and krill oil can interact with the following drugs:7

  • Anticoagulants and Antiplatelet drugs – Bleeding risk may increase.
  • Antidiabetic drugs – Hypoglycemia risk may increase.
  • Orlistat – May decrease the absorption of krill oil or fish oil.

Should You Take Krill Oil or Fish Oil?

Although the evidence isn’t substantial, I prefer krill oil.  My reason for this is that it may be more bioavailable and has the additional benefit of containing an antioxidant.  Krill oil is not hard to find, and it doesn’t cost that much more to obtain.  Krill oil also doesn’t have the fish odor associated with fish oil supplements. 

It is crucial to ingest essential fatty acids for the proper functioning of the body.  These molecules are important for our cell membranes and  proper brain and nerve function.  Always remember that getting these fatty acids from your diet is a better choice than taking supplements.  The healthiest way to live is to eat a well-balanced diet utilizing mostly whole foods, drink plenty of water, exercise regularly, and get an adequate amount of sleep.

If you don’t believe you are getting enough essential fatty acids, then take a supplement.  I prefer krill oil for the reasons stated above, but fish oil is also a good choice.  Be sure to talk to your physician or pharmacist if you are allergic to shellfish before taking krill oil.  If you use blood-thinning medications, always check with your physician or pharmacist prior to taking any supplement. 

I am always happy to answer questions regarding drugs or supplements.  Send me an email, and don’t forget to sign up for our monthly newsletter below.  You will receive company news and coupon codes for savings on all of our products.

Have a great week, and be happy and healthy.

Michael Brown in Lab Coat with arms crossed

Michael J. Brown, RPh, BCPS, BCPP

Mr. Brown is a Clinical Pharmacist specializing in pharmacotherapy and psychiatry.

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