There is a website dedicated to Independent cancer study analyses. One of their parasite focussed Publications covered one of the seven herbs listed in dr. Zhang's non-moving Lyme disease killing study.
Have you read about this?
The publication also disclosed that the whole plant herb had other compounds that killed the target parasites. That's why it's 40 times more effective then the pill concentrate.
Furthermore, one or more of the doctors who prescribe the pill version says it should be taken with an oil, and with food if you are taking the pill version.