uses JavaScript to provide the best possible experience for our content, but your browser has it disabled. Learn how to enable it here.


DHA and EPA Levels in Fish Oil -- close-up of fish oil capsules


Although research continues to clarify the roles of DHA and EPA, some evidence suggests that DHA may be more important in certain situations, while EPA may be more important in others.  Keep in mind, however, that participants in most studies were not eating diets rich in DHA or EPA (i.e., not eating fish at least twice a week). It’s not clear that any type of fish oil supplement will provide value if you are already getting substantial amounts of EPA and DHA naturally from foods. In fact, in terms of general cardiovascular benefit, it’s pretty clear that you are better off eating fish (not fried!) than taking a supplement.  But if you won’t eat fish or other foods rich in EPA and DHA, consider taking a supplement.

Here are some of the benefits which have been seen with EPA and DHA supplementation:

  • Pregnancy -- DHA is important during pregnancy for normal development of the infant and may decrease premature births. Pregnant women should get at least 200 mg of DHA per day from a supplement or low-mercury fish.
  • Periodontitis -- High-dose DHA has helped improve periodontitis (inflammation around the teeth causing pocketing), although this was not seen with high-dose EPA.
  • Age-related Cognitive Decline -- Studies have shown a modest benefit with a supplement high in DHA. A supplement high in EPA did not have this benefit.
  • Depression -- Large amounts of EPA relative to DHA may help relieve depression in cases of moderate to severe depression (not mild depression).
  • Anxiety -- A supplement high in EPA helped reduce anxiety in students.
  • Chemotherapy -- A supplement providing a large amount of EPA has helped prevent weight loss during cancer chemotherapy.
  • Alzheimer's disease -- A supplement containing more EPA than DHA helped slow cognitive decline in patients with Alzheimer's disease. This has not been seen with supplements higher in DHA. However, no omega-3 supplement can reverse Alzheimer's disease.
EPA and DHA:
  • Acne -- A high-dose combination of EPA and DHA helped reduced the number and severity of acne in men and women.
  • Strength training -- More equal combinations of EPA and DHA have helped improve strength during strength training in a study of older women.
  • High triglycerides -- Very high doses of EPA and DHA from concentrated fish oil can lower triglyceride levels.
More details (including dosage) about each of these uses are found in the What It Does section of's Fish Oil and Marine Oil Supplements Review>>  In the Review, you'll also find's tests and comparisons of supplements containing EPA, DHA and other fatty acids from fish, krill, algal, and other marine oils.

Join today to unlock all member benefits including full access to all CL Answers and over 1,300 reviews.

Join Now

Join now at


Join the conversation

January 28, 2016


How much EPA should you have to help with depression and anxiety
January 31, 2016

Hi Kirsten - You can find this information in the "Dosage" section of the Fish Oil Review:

January 27, 2016

I'm trying to learn which supplement would be generally better to take - fish oil or krill oil? Where can I see a study or recommendations from ConsumerLab on that subject?
February 8, 2016
neelam 430
January 27, 2015


Is it better to have farm developed salmon or wild Alaskan version? Which would have less metal pollution ?

February 8, 2015

Hi Neel - We've now answered your question here:

Kate An429
January 26, 2015

I've tried a number of fish oil supplements, all of which make me nauseous. What is the best non-fish alternative? I am primarily interested in getting EPA.
January 28, 2015

Hi Kate - Thank you for your question. This is something others may have experienced also, so we have now answered this here:

Donna 8402
January 27, 2016

Try freezing the caplets and/or taking them with ginger tablets.

January 25, 2015

Eating fish may or may not be better than taking a supplement. Has that choice been sorted out and replicated in a randomized prospective trial? Not as far as I know. Also, some large fish (e.g., swordfish, others) may contain unhealthy quantities of heavy metals, whereas supplements do not.
January 26, 2015

Hi John - As you noted, and as we discuss in detail in our Fish Oil Supplement Review, fish meat is more contaminated than fish oil, and particular fish should only be consumed in moderation. However, regarding general cardiovascular benefits, the studies are now pretty clear that eating fish is better than taking fish oil. See our report for details about this: In addition, studies showing a benefit with fish oil have usually been conducted among people who do not regularly eat much fish.

December 6, 2020

I really appreciate all your information on Omega 3.....very comprehensive. What I would like to see is your review of Omega 3 in Purity Products. I have been taking Krill Omega 10X for 3 years for Dry Eye. It works! My optometrist recommended 2,000mg with DHA slightly higher than EPA At beginning of pandemic Purity was out of this product for almost 2 months....I tried others: Carlson and a different one at Purity...none did the job for my dry eye. Please DO review Purity Products: for many years now I have been taking various products and very pleased with their efficacy. Cathy Humeniuk

Join today to unlock all member benefits including full access to CL Answers

Join Now

Join now at