Half of Top-Selling Glutathione Supplements on Amazon Fail Label Claims in Independent Testing, Cata-Kor Reports

Cata-Kor, a nutraceutical company specializing in supplements in the longevity category, recently announced that six of 12 glutathione supplements failed to meet potency claims in an independent testing panel it commissioned.

Testing was done by Swift Laboratory, an SIO 17025:2017-accredited third-party testing facility, using high-performance liquid chromatography, which is standard for quantifying reduced glutathione in dietary supplements.

The findings point to a quality problem in glutathione products on Amazon, particularly for those marketed as high-dose or liposomal.

Products were purchased on Amazon between the months of April and June, and were submitted to Swift Laboratory for independent analysis. Glutathione content was quantified by HPLC per serving as stated on each product label.

Key Findings

Of 12 brands tested, six failed to contain the stated amount of glutathione, Cata-Kor reported.

• Zeylamum, which claimed 1,300 mg of L-glutathione per serving, had no detectable glutathione.
• Cenffito, which claimed 600 mg, contained no detectable glutathione.
• Starehonorr claimed 1,000 mg and returned less than 20 mg.
• Prunucis, claiming 1,200 mg, returned only 31.6 mg.
• Corporalight claimed 1,500 mg and returned 256 mg.
• Alpha Flow, claimed 1,100 mg and returned only 311 mg.

Six brands – Dr. Mercola, BodyBio, Terra Elmnt, Deal Supplement, Fresh Nutrition, and Cata-Kor, met or exceeded their label claims.

Cata-Kor’s Liposomal Glutathione supplement passed testing across all measured parameters, confirming 1,082 mg against the label claim of 1,000 mg. The same test confirmed accuracy for all co-ingredients: vitamin C (64.8 mg versus 50 mg claimed); riboflavin (6.79 mg versus 5 mg claimed); selenium (71 mcg versus 55 mcg claimed); and resveratrol (114 mg versus 110 mg claimed). Heavy metals testing confirmed results were within USP’s safety limits.

“Label accuracy is the baseline, not the differentiator,” said Roman Miroedov, PhD, product development lead at Cata-Kor. “When six of 12 products we tested failed to deliver what the label claims, that is a consumer protection issue. We are publishing these results because buyers deserve to know what they are actually getting.”