After identifying prevalent quality issues among several popular creatine, NAD+, and urolithin A products, digital health platform and third-party product evaluator SuppCo recently found that more than half of 13 top-selling Berberine products purchased on Amazon failed to achieve 50% of the berberine potency claimed on the label.

More than half of the brands tested appeared to contain less than 10% of the claimed amount of berberine; gummies, including those with the most reviews, were the worst offenders, containing no detectable berberine.

The company noted that products advertising higher doses of 1500 mg or greater were the most likely to fail.

Further, cheaper products were also likely to fail; brands under $25 were far more likely to fail testing. “This doesn’t mean all higher-priced supplements are guaranteed to be accurate, but the trend was clear, brands charging more often delivered what they promised, while lower-priced products were more likely to cut corners.”

Ratings on Amazon weren’t reliable indicators of quality. Six of the seven failing brands had an “Amazon’s Choice” label or an average consumer rating of over 4.3 stars failed. “Shoppers may assume these signals equal trust, but in reality they can amplify products that are popular for marketing reasons while failing at the most important task: delivering what’s on the label.”

Interestingly, products that promised “enhanced” delivery technologies, such as liposomal and phytosomal products, intended to help solve berberine’s well-known issues with oral bioavailability, contained dramatically less berberine than advertised, and sometimes effectively none. “While a delivery technology may have scientific merit, its current marketplace execution is inconsistent, with some brands relying heavily on buzzwords like ‘liposomal’ to justify higher prices without actually delivering the ingredient in usable amounts … not all innovation claims translate into quality.”

Testing Panel Details

In total, seven of 13 products failed SuppCo’s testing, and most contained less than 2% of claimed label content. Meanwhile, the six passing brands contained over 100% of claimed berberine.

The two gummy products evaluated contained no berberine at all, which was similar to SuppCo’s creatine report, which found that four of six gummies failed.

Failing brands, on average, cost $25, while passing brands were slightly more expensive at an average of $33.

SuppCo noted that it tests its products based on how popular they are among the user base of its app, and the most talked-about supplements on the market. Each product is bought anonymously and sent to an ISO 17025-accredited lab, and failing products are tested again to confirm results.

For dosing considerations, “stick with the standard capsule formulations from trustworthy brands that pass independent testing. A realistic serving size (often 500 mg taken two to three times daily with meals) is both aligned with the clinical literature and more reliable at this point, as opposed to chasing exotic delivery claims,” the company reported.

The company noted that, as a result of its rounds of testing, several SKUs have been pulled from major retailers after failing tests; multiple companies have reformulated products or updated labels following issues on SuppCo tests; brands are reaching out to be included in the company’s testing, though it doesn’t test upon request; and SuppCo charts and tables are now showing up in Amazon customer reviews, with certain customers calling out poor-performing products directly on product pages.

To read the full report, click here.