357 analytical chemistry assays on the 53 best-selling fish oil supplements in the United States.
Label accuracy was a major issue for fish oil supplements. Total omega-3 content ranged from -60.0% to +62.5% versus their stated label claims.
Chewable and Liquid-formulated fish oil supplements contained much lower EPA + DHA concentration than their softgel counterparts.
Labdoor analyzed 53 best-selling fish oil supplements in the United States, measuring total omega-3s, EPA and DHA, vitamin D, and CLA content, methylmercury concentration, and total oxidation values.
31/51 products demonstrated omega-3 levels that varied by over 10% off their label claims, 18 of which recorded a 25% variance between actual versus claimed content. EPA+DHA content also showed significant ingredient variance, ranging from -25.3% to +32.7% versus its stated label claims.
All but 4 products contained measurable amounts of mercury, with 3 products recording 50% or greater of the allowable mercury content/serving. The majority of products passed oxidation (freshness) assays, although 14/51 products recorded peroxide levels (measure of primary oxidation) at or above the upper limit.
EPA+DHA content ranged from -25.3% to +32.7% versus its products' stated label claims.
14/51 products recorded peroxide levels (measure of primary oxidation) at or above the upper limit.
Non-softgel fish oil supplements contained far lower concentrations of EPA and DHA content, likely due to the addition of inactive ingredients like fillers and sweeteners.
All but 4 products contained measurable amounts of methylmercury, with 3 products recording 50% or greater of the allowable methylmercury content per serving.
Based on current scientific research, existing international standards, and recommendations from medical experts, Labdoor used a daily intake target of 1000mg of total omega-3 content, including 400mg of EPA and 600mg of DHA, for the purposes of our calculations.