Contamination and other problems found in fish oil supplements

The quality of fish oil / omega-3 supplements varies across brands, according to recent tests by, which independently reports on the quality of health products. 

Analyses of 35 products selected and purchased by showed problems with the quality or labeling of 11, or 31.4%, of the products. uncovered the following problems:

  • Trace levels of PCBs were found in every product (as PCBs are ubiquitous in water), but two supplements exceeded contaminations limits for PCBs.
  • Mercury was not detected in any of the products.  (While it is best to avoid supplements with excess contaminants, raw or cooked fish may contain far more PCBs, as well as mercury, than fish oil supplements.)
  • Four supplements (including one of the contaminated products) contained 20% to 30% less than the claimed amounts of EPA, DHA or other omega-3 fatty acids.
  • An enteric-coated softgel (intended to reduce “fish burp”) released its fish oil too early.
  • One softgel product contained spoiled fish oil.
  • Three products contained two to three times the claimed amounts of EPA or other fatty acids, and one supplement incorrectly claimed to contain 1 mg of fat but contained 1,000 mg (1 gram) of fat.

The tested supplements include those with fish oil, krill oil, algal oil (from algae) and/or, calamari (squid) oil.

Results are published in a new report on which provides results for the 35 selected products as well as 28 products which passed the same testing through’s voluntary certification program.

The review covers products for general use and those marketed specifically for pregnant women and children. It also includes pet supplements for use by dogs and cats. found that good quality fish oil could be had for as little as 1 cent per 100 mg of EPA and DHA (a typical daily dose is 300 mg to 500 mg).

Krill oil was much more expensive – the lowest cost being 19 cents per 100 mg of EPA and DHA.

Calamari oil and algal oil tended to be priced between the two other oils. cautioned that some “krill oil” supplements are actually blends of fish and krill oils and their labeling is misleading.

Some products also claim to provide a certain percentage of the Daily Value (DV) for EPA and DHA – but no Daily Value has actually been established for omega-3 fatty acids.

The new report is available online to members at

In addition to quality ratings of supplements, the report includes extensive clinical information about the use of fish oil and omega-3 fatty acids for cardiovascular disease, arthritis, cancer, eye disease, psychiatric and cognitive disorders, and in pregnancy. It also provides expert tips on how to buy and use fish oil and other marine oil supplements, and information about dosage, potential side effects, and drug interactions.


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