Cata-Kor has published results from its testing of berberine supplements sold on Amazon, revealing a large proportion of the products contained far less berberine than their labels state.
Of 20 products, the nutraceutical company found that seven failed to meet their label claims, with one containing no detectable berberine at all.
The study is the second in an independent series Cata-Kor is conducting, having already investigated and published results on the twelve top-selling glutathione supplements on Amazon — half of which also failed to meet their label claims.
Twenty products were selected from Amazon.com search results for the keyword “berberine" — one product did not state its berberine content on the label and thus could not be rated. Products were bought in August and September 2026.
Swift Laboratory completed the testing in an ISO/IEC 17025:2017-accredited lab, using HPLC to quantify the amount of berberine in each product, with results applying to the specific lot tested.
The results
According to Cata-Kor, seven of the twenty supplements tested failed to meet their label claims, with four delivering five per cent of the stated dose or less.
The longevity company said one product contained no detectable berberine — but had claimed 1500 mg per serving.
On a positive note, twelve products met or exceeded their label claims and none of the samples failed microbiological screening.
| Company name | Berberine label claim (mg) | Actual berberine content (mg) | Percentage of the claim |
|---|---|---|---|
| Jingyat | 1500 | No detectable berberine | 0 |
| Cealmu Core | 1500 | 33.8 | 2.3 |
| Aumeto | 600 | 29.8 | 5 |
| VEV | 800 | 40 | 5 |
| Monte Vera | 1500 | 183 | 12 |
| Nature Target | 1200 | 295 | 25 |
| Zebora | 1200 | 315 | 26 |
Cata-Kor said Zebora's label listed ingredients that should add up to 1320 mg, but the lab recorded that the total powder in a two-capsule serving weighed 893 mg instead — a considerable shortfall, raising concerns about the accuracy of the product's declared composition and whether consumers are receiving the berberine dose they are paying for.
A different product from Decent Nature listed 1800 mg of organic berberine extract (4:1) per serving, but did not state how much berberine the extract contains.
While Cata-Kor said the lab testing detected 199 mg of berberine HCl per serving, it was impossible to determine whether the measured amount met the label claim without a specified amount of berberine per serving on the label.
“Someone who buys a 1500 mg berberine supplement and gets almost none of it has no way to find out. They take it for a couple of months, see no change and decide berberine doesn’t work for them, while the bottle keeps selling,” said Vlad Seuruk, CEO of Cata-Kor.
After the glutathione results, we expected berberine to be next in line, because demand has grown so fast. Most of the products we tested hit their numbers, which shows that accurate dosing is entirely achievable.
The twelve products that met or exceeded their label claims were the following: Dr. Berg, Force Factor, Luma Nutrition, Micro Ingredients, Ultra Herbs, Doctor Recommended, ForestLeaf, Integrative Therapeutics and Cata-Kor Liposomal Berberine.
Three products containing dihydroberberine, a derivative of berberine, were tested against their label claims and met or exceeded them: Nature’s Fusions, Peak Performance and BIOptimizers.
All 20 samples passed microbiological screening, including tests for E. coli, Salmonella, yeast and mould.
