Goldenseal is one well-known example of a berberine-rich plant and enjoys a long history of medicinal use by Native American tribes. Berberine has recently risen in popularity on social media as a dietary supplement. With such a rise in popularity, there is the possibility for deceptive players to take advantage of the increased demand by offering inferior or adulterated products. This is the 16th round of product testing performed by NOW since 2017. 

Berberine supplements (like NOW’s) are typically made in hydrochloride (HCl) form, which is obtained from an extraction of Berberis aristata bark. Berberine HCl dihydrate is typically used as the supplement source of Berberine HCl and is 85-90% potency. This means if brands claim 500 mg Berberine on a label and it is in the HCl form, the supplier must input 550-575 mg Berberine HCl dihydrate to meet the label claim. Some brands claim “Berberine” in the Supplement Facts panel for potency, while others list “Berberine HCl”. While both are technically legal, full disclosure would list like: “Berberine HCl 500 mg (from 550 mg Berberine HCl dihydrate)”. Therefore labeling, testing and calculations are complicated. 

We purchased two bottles of each product from 33 brands (including NOW) sold on both Amazon and Walmart.com. It was suspicious even before testing that many brands may be fraudulently mislabeling potency on the front label panel due to high potency claims. The quality of each brand was assessed by high-performance liquid chromatography (HPLC) with ultraviolet light detection (HPLC-UV). HPLC was also used to quantify the amount of berberine hydrochloride in tested products. 

Externally, NOW sent one unopened bottle of each brand to Alkemist Labs to provide an independent report on the same products. HPLC was performed by both NOW’s in-house lab as well as Alkemist Labs, an industry-leading contract laboratory we partnered with on a previous round of marketplace testing. 

Below are highlights of this testing group, as well as detailed assay results: 

• The products chosen were purchased from both Amazon and Walmart.com in early November 2023. These brands were picked because they are less known and sold almost entirely on these platforms. We have avoided testing health food store brands or practitioner brands as being less of a concern. 
• The results of this round of testing showed serious levels of low potencies with every brand testing below 100% potency, except NOW. Seven brands did contain over 80% labeled potency and three brands contained 90-97% potency. 
• NOW has tested some of the same brands previously, while testing other categories, and found similar problems. aSquared brand has failed eight different rounds of product testing and has the worst record for potencies tested among all brands. 
• 18 of the 33 brands tested contained less than 40% of labeled potency. That’s more than half of all brands tested that didn’t even contain a mediocre 40% level of potency. 
• 7 of the 33 tested samples had 1% or less of Berberine potency in each product. It appears that all of these seriously flawed brands were tested for the first time in NOW’s testing program and may be new brands. These include Earth Bare, Greabby Gummies, GreenPeople Formula, KoNefancy, Satoomi, Vitamiscence & Wellness Labs Rx.