A comparison of actual versus stated label amounts of EPA and DHA in commercial omega-3 dietary supplements in the United States

Background: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with health benefits throughout life and are obtained primarily through fish and fish oil supplements. Due to the growing popularity of dietary supplements, 47 commercial fish, krill, and algal oil supplements were analyzed for EPA, DHA, and other fatty acids.

Results: For fish- and krill-based supplements, the range of EPA was 81.8 to 454.6 mg g(-1) oil and DHA was 51.6 to 220.4 mg g(-1) oil. For algal oil supplements, EPA ranged from 7.7 to 151.1 mg g(-1) oil and DHA ranged from 237.8 to 423.5 mg g(-1) oil. The percentage of the stated label amount for EPA and DHA ranged from 66 to 184% and 62 to 184%, respectively. Only 10 supplements (21% of those tested) had at least 100% of the stated label amount of EPA, while 12 supplements (25% of those tested) had at least 100% of the stated amount of DHA. Over 70% of the supplements tested did not contain the stated label amount of EPA or DHA.

Conclusions: These results indicate that the quality of fish oil supplements is not being adequately monitored by manufacturers or government agencies and increased testing is needed to ensure regulatory compliance.