357 analytical chemistry assays on the 52best-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 52 best-selling fish oil supplements in the United States, measuring total omega-3 content, EPA and DHA quantities, vitamin D and CLA amounts, methylmercury concentration, and total oxidation values.
31/52 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.
Every product 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 14/52 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.
14/52 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.
Every product 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.