Inauthentic Herbals

Using DNA barcoding, researchers show that herbal products are often contaminated or contain alternative compounds and fillers.

Tracy Vence
Nov 6, 2013

Phyllanthus bahiensisFLICKR, ALEX POPOVKINNaturally, consumers reaching for herbal remedies may think they are doing their bodies a favor. But a new DNA barcoding study has shown that some of these so-called “natural” products are contaminated, containing substitute ingredients and fillers that are anything but. The results were published in BMC Medicine last month (October 11).

Researchers from the Biodiversity Institute of Ontario at the University of Guelph tested 44 herbal products produced by 12 manufacturers and sold in the U.S. and Canada. They found that 59 percent of those products contained DNA barcodes from plant species not listed on their labels, and a third of the products contained undeclared contaminants and/or fillers. In their paper, the researchers noted that substituting ingredients and adding filers can dilute the otherwise helpful activities of certain plant species.

“The level of regulation of herbal products is not good enough,” Graham Lord, director...

To that end, the Guelph team also presented in BMC Medicine a standard reference material herbal barcode library including “100 herbal species of known provenance that were used to identify the unknown herbal products and leaf samples” in its investigation.