recent news that many herbal supplements don't have any herbal content.

This just in! Tests showing herbal supplements don't have any herbal content might be all wrong. It seems they looked for the DNA of the claimed herbs, and "DNA barcoding would probably not find DNA even in perfectly kosher herbal supplements if they involved herbal extracts rather than the herb itself. Making an herbal extract involves heavy processing, and any DNA would likely be destroyed."

Curiously, the writer of that article considers it dreadful news that the supplements might contain exactly what the makers say they do, on the grounds that herbal supplements are a dodgy business, so any evidence that they're doing something right is a soldier on the wrong side.