Fact checked by Nick Blackmer
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Fish oil pills are a popular supplement choice: One in five U.S. adults older than 60 reports taking them often. Despite sometimes conflicting research on their effectiveness, many people turn to them for improved heart health, cognitive performance, or to reduce inflammation.
But some of these supplements may have quality issues, according to new data from Consumer Reports. The consumer advocacy group found that 20% of 20 common brands tested did not meet standards for freshness, heavy metal levels, or EPA and DHA content—the two main omega-3 fatty acids found in fish oil.
What Consumer Reports Did
Consumer Reports tested fish oil supplements—the first time since 2012—to inform the public about potential risks from contaminants and to urge manufacturers and regulatory agencies to improve supplement quality if issues were found, Tunde Akinleye, a researcher with the nonprofit who was involved in the testing, told Health.
The testing included 20 popular fish oil products representing top-selling national, store, and private brands, Akinleye said. Researchers tested samples for three factors:
- Rancidity: This is a measure of freshness, or whether the omega-3s had degraded through oxidation. Results were compared with the total oxidation limit set by the Global Organization for EPA and DHA Omega-3s (GOED), an industry group.
- Heavy Metals: Levels of metals such as arsenic, cadmium, lead, and mercury were measured and held up against standards set by various public health agencies, including California Proposition 65, the European Food Safety Agency, and the U.S. Environmental Protection Agency.
- EPA and DHA content: Researchers used gas chromatograph-mass spectrometry to check levels of the fatty acids EPA and DHA in each sample. To meet quality standards, products needed to contain at least 90% of the amount of EPA and DHA listed on their labels.
The Results
Sixteen of the 20 fish oil supplements either met standards across categories or met standards but couldn’t be tested for rancidity. These included products from 365 Whole Foods Market, CVS Health, Barlean’s Organic Oils, Nature’s Bounty, and more.
However, four products either failed to meet label claims for omega-3 content or showed signs of rancidity:
- California Gold Nutrition Kids Omega-3 Fish Oil Softgels, Strawberry
- Kirkland Signature (Costco) Fish Oil Softgels, 1000 mg
- Nature Made Burp-Less Fish Oil Softgels, 1000 mg
- Qunol UltraOmega-3 Mini Softgels. 1000mg
These results may offer important guidance for people who take fish oil, said Carolyn Lam, MBBS, PhD, a senior consultant cardiologist at the National Heart Centre Singapore and a professor at Duke-National University of Singapore Medical School.
“I think Consumer Reports' methodology is sound and results carry an important take-home for consumers: a fish oil bottle on the shelf is not necessarily delivering what its label promises, and may not even be fresh,” she said. “That is reasonable cause for caution.”
However, a representative for Nature Made told Health that internal testing found its Burp-Less Fish Oil Softgels were well within GOED standards for oxidation. “As fish oil products reach the end of their shelf-life, peroxide levels naturally and expectedly increase, but that does not impact product efficacy, with the only notable consumer experience difference being a slight change in aroma,” the representative said.
Health did not hear back from the three other supplement companies by the time of publication.
Do You Need Fish Oil?
Despite fish oil’s heart-healthy reputation, scientific consensus doesn’t necessarily support taking it for general cardiovascular wellness.
In fact, a 2026 report from the American College of Cardiology and American Heart Association recommended against nonprescription fish oil due to a lack of evidence for clinical benefits and potential adverse effects, such as increased LDL cholesterol and atrial fibrillation.
“We know that having fish oil in your diet from fish itself seems to confer advantages in heart health, but that data for supplements has not been as strong,” said Srihari Naidu, MD, a cardiologist and professor of medicine at New York Medical College.
Still, Naisu said there’s some evidence that fish oil may help lower triglyceride levels and reduce blood pressure, so for people with high triglycerides or hypertension, he believes it can be a reasonable addition to care.
Your doctor can help you determine whether adding a fish oil supplement is worthwhile for your health.
How to Find a Supplement That’s Safe and Effective
So how can you ensure you’re purchasing a supplement that’s both safe and effective?
Start by looking for products that have been third-party tested, which can help verify omega-3 content and check for contaminants, said Ganesh Halade, PhD, a professor at the University of South Florida Heart Institute. Look for seals from organizations like USP, NSF, ConsumerLab.com, Informed Sport, and Labdoor. If you want to dig deeper, you can also contact individual brands for information on internal testing or quality assurance practices.
And unless your doctor has specifically recommended a fish oil supplement, focusing on food sources may be a better option. “Getting omega-3s from whole foods, such as nuts and fatty fish, is generally preferred over relying only on supplements,” Halade said.
