http://www.newscientist.com/article/dn2 ... ation.html
RosieA study has revealed that almost 60 per cent of common herbal supplements sold in the US and Canada contained products not listed on the label, some of which could pose serious health risks to consumers. Steven Newmaster at the University of Guelph in Ontario, Canada, and his colleagues used a sequencing technique called DNA barcoding to identify plant material in 44 herbal products from 12 companies. He compared those to leaf samples of known provenance. In 32 per cent of the samples containing unlisted plant species, the main plant had been replaced with something else. Some also contained unlabelled fillers such as grass, wheat or rice.
