183 analytical chemistry assays on 51 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 concentrations than their softgel counterparts.
LabDoor analyzed 51 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.
21/51 products demonstrated omega-3 levels that varied by over 10% off their label claims, 15 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 per serving. The majority of products passed oxidation (freshness) assays, although
1 product recorded a TOTOX score above the upper limit and 6 more products measured within 5% of the upper limit.
FISH OIL |
LABDOOR’S QUALITY RANKING
Compares products based on their label accuracy, manufacturing purity, nutritional value, ingredient safety, and projected efficacy.
FISH OIL |
LABDOOR’S VALUE RANKING
Compares products based on their quality score and average price.
SCIENTIFIC TESTING RESULTS
FISH OIL | LABEL ACCURACY
Total omega-3 content varied by an average of 24.3% versus the stated label claims,
compared to a 31.6% average variance in EPA content and a 20.3% average variance
in DHA content.
Nature Made Cod Liver Oil, MET-Rx Fish Oil with Vitamin D, and Top Secret Nutrition
Fish Oil & CLA were all penalized for failing to disclose EPA & DHA content
on their product labels.
Nature Made Fish Oil was ranked #1 in overall label accuracy, recording just a
2.8% variance in total omega-3 content and measuring within 5% of its EPA &
EPA+DHA content ranged from -25.3% to +32.7% versus its products' stated label claims.
FISH OIL | PRODUCT PURITY
Every fish oil supplement contained measurable amounts of mercury, with the category averaging
2.9 PPB (parts per billion) of mercury. LabDoor set its upper limit for mercury content at 10 PPB.
The worst offenders were Nature Made Cod Liver Oil and Natrol's Omega-3, which both recorded
mercury levels of 6 PPB.
Our scientists also focused on each oil's freshness, measured by the degree of oxidation.
Oxidation occurs in two phases: primary (measured by peroxide values) and secondary (measured
by p-anisidine values). Total oxidation is formalized into a quantitative score, TOTOX. All
products recorded measurable levels of oxidation; the category averaged a TOTOX score of 21.3
(Upper Limit = 26). The majority of products measured scores above 20.
12/51 products recorded peroxide levels (measure of primary oxidation) at or above the upper limit.
FISH OIL | NUTRITIONAL VALUE
Each product's Nutrition Facts label was algorithmically analyzed to compare total calories,
fat, saturated fat, cholesterol, and carbohydrate content per serving. Additionally, all vitamin
content was compared to established upper limits for these nutrients.
Our scientists also measured the concentration of EPA + DHA content in each serving. Average
EPA/DHA concentration was measured at 41%, a figure that ranged from 2-94% in the 51
products analyzed in this study.
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.
FISH OIL | INGREDIENT SAFETY
Fish oil safety is strongly tied to product purity. Contamination (mercury concentration)
and rancidity (TOTOX score) both may contribute to the development of adverse health effects.
Added inactive ingredients also contribute to product safety. Eight supplements in this study
contained ‘natural’ flavors such as citrus-derived additives. One product, Coromega
Omega-3, also contained benzoic acid, a popular antibacterial agent linked to carcinogenic risks
when combined with vitamin C.
Every product contained measurable amounts of methylmercury, with 3 products recording 50%
or greater of the allowable methylmercury content per serving.
FISH OIL | PROJECTED EFFICACY
Omega-3 fatty acids are clinically shown to improve cardiovascular conditions (including hyperlipidemia,
coronary heart disease, and hypertension) and, according to limited evidence, may also improve cognitive
performance, reduce anxiety, enhance athletic performance, and reduce the risk of certain types of cancer.
Fish oil supplements in our study averaged 435.7mg EPA + 239.8mg DHA in a single serving. These average
values were stretched by outliers on both extremes of the spectrum. Nature Made Cod Liver Oil measured
only 50mg EPA + 50mg DHA per serving while Dr. Tobias Optimum Omega-3 Fish Oil recorded a category-high
920mg EPA + 600mg DHA per serving (460mg EPA + 300mg DHA per capsule).
As a point of reference, Lovaza, an FDA-approved omega-3 supplement, contains 465mg EPA + 375mg DHA
Based on current scientific research, existing international standards, and recommendations from medical
experts, LabDoor set a daily intake standard of 1000mg EPA + DHA, consisting of 400mg EPA and 600mg DHA,
for the purposes of our calculations.