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Fish Oil


Long-term use of fish oil is safe as long as the daily dose is not too high and the fish oil is not contaminated, as discussed in the Concerns and Cautions section of our Fish Oil Supplements Review. In fact, long-term daily use of fish oil is safer than eating fish each day due to much higher amounts of mercury in many types of fish. In contrast, there is essentially no mercury in fish oil, as it binds to proteins and not oils. PCBs, however, can be found in fish oil as well as fish meat.

The concern with too much fish oil is the potential for suppression of the immune system, which may occur at daily doses above 2,000 mg of EPA and DHA. Be aware that fish oil may also have a blood thinning effect and may lower blood pressure.

Despite some concern, there is no good evidence that taking fish oil long-term increases the risk of fatty liver disease. Although one animal study showed that lifelong feeding with fish oil caused certain changes in the liver that might make the liver susceptible to fatty liver disease, other observed changes were believed to help the liver adapt to aging. These results have not been replicated in people.

Keep in mind that you may be better off eating fish twice a week than taking fish oil, as there is more evidence of cardiovascular benefit from eating fish than from taking fish oil. If you already eat fish twice a week, taking a fish oil supplement may offer no additional benefit, unless you are trying to reduce elevated levels of triglycerides with high-dose fish oil.

Of course, if you don't eat fish twice a week, you should consider supplementing with fish oil, as the omega-3 fatty acids in fish oil may help with inflammatory diseases, eye disease, mental health disorders, and even the prevention of some types of cancer.

Be aware that taking fish oil containing large amounts of vitamin A (as is common in fish liver oils such as cod liver oil) can cause liver toxicity, particularly if taken with other supplements containing vitamin A.

For more information, as well as our tests of many popular fish oil supplements, see the Fish Oil Supplements Review >>

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December 16, 2019

Im worried about alot of the premium fish oils contain soy. I will not ingest soy. So take a lower epa fish oil to elminate unwanted ingredients. THere is always alot to study before purchasing. I have been researching for 2 hours before going to the store tomorrow. brain is hurting!
December 17, 2019

Some fish oils contain soy oil, but many do not. To easily find out, you can look at the ingredients comparisons in our Fish Oil Review, which includes the full listing for each product as well as listed allergen warnings. Of course, before you buy a product, be sure to check its label -- as formulations can change over time.

January 4, 2018

Should we be concerned about potential neurotoxin/BMAA in these products that is thought to cause neurodegenerative diseases?
January 4, 2018

Hi Doug - We are not aware of any issue with BMAA in fish oil supplements. Fish and krill used for supplements are typically from cold water, while BMAA is from cynanobacteria typically found in warmer water.

Benjamin Lev22048
February 8, 2021

Hello, there is data that fish oil supplements might *increase* high-risk prostate cancer. Can you confirm or report on this? Thanks
February 10, 2021

Hi Benjamin - Please see our CL Answer about supplements and prostate cancer risk You can also find more information about this in the "What It Does" section of the Fish Oil Supplements Review

January 4, 2015

Since when did consumerlab start allowing comments? This doesn't seem like a sane maneuver.
January 5, 2015

Hi Daniel - We began allowing comments in 2014 in order to permit an exchange of information from our members. We review each comment prior to actual posting.

December 16, 2019

I think it is excellent idea to allow comments! I have learned so much from COnsumer Labe and viable comments on here! THANK YOU CONSUMER LAB for allowing us to comment on subjects important to us. And things that we can share to help others!

January 1, 2015

i don't agree that eating fish 2x per week is better than taking a "good" fish oil supplement. there is much evidence that most fish that is readily available now, including salmon is contaminated since most of the seas is also polluted now. presence of dioxin in fresh water fishes such as tilapia, cream dory/pangasius/white cobbler, catfish, mercury in tuna and other large fishes is more toxic than taking any fish oil supplement. and since everyone is not short of bad cholesterol, it is an " essential" fatty acid , and beyond this, the anti aging and anti inflammatory benefits is important in preventing degenerative diseases.
provided you get good brands of antartica krill fish oil that is standardized and from a very reputable source such as the one i am taking. it even stabilized the lupus of my friends sister

January 2, 2015

Is Krill really fish? I think it is tiny shrimps or crustaceans. What we humans really need to do is to realize that if humans keep reproducing, that even Antarctica is going to be polluted. We keep running, breathlessly, in front of the jabbing sword of human ignorance, hoping that our personal intelligence will keep us from the overcoming tsunami wave of human overpopulation. When Planet Earth's vast oceans, which take over 2/3rds of the earth's surface, become so polluted that we cannot even eat fast swimming deep cold water fish, then humanity is in Deep Trouble. We better work on the primary problem so that our grandchildren have something to stay healthy for!
January 3, 2015

Krill are not fish, but krill oil supplements are included in the same review as fish oil supplements, as that review focuses on omega-3 fatty acids from marine sources. Interestingly, we have found that some "krill" products often contain fish oil, although this is not always clear from labeling.

You can read more about this in the "Fishy Labeling" section of the Review:

November 12, 2017

Anise, you have it. Overpopulation is the scourge of this earth plus overconsumption and waste. Greed is in there, too. When will the people wake up and see what we are doing to our poor Mother Earth. She's the only planet we have, our home. It will be sad - catastrophic - if we don't act NOW.

December 31, 2014

Carlson Fish Oil is best, purest and freshest and should be taken in the morning with breakfast as a liquid in a spoon. It gets into your system immeidiately that way. It is good for your eyes and your heart and many other metabolic daily needs.

Fish from the ocean carries its toxins in the flesh and that is why I don't eat much fish anymore. It's poorly harvested by ignorant corporations and contains too many toxins unless it comes from very cold Nordic waters in the form of small fishes like sardines. I love the flavor of cooked fish, but do not enjoy it anymore because of world overpopulation of humans and their waste entering our oceans and waterways. Let's stop producing humans, eh? Maybe we could clean up the planet and maintain at a mere 2 billion instead of 8.

January 4, 2015

good idea

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