Traditional Chinese medical practitioners understand that yin, yang and chi constantly interact in the body to maintain health. Western medical practitioners understand how to use agonists and antagonists and how to modify signalling processes, but generally do not accept the use of complex plant extracts to perform these functions. Aimed at medical scientists, and including detailed explanations of the theories behind the science, this text may help researchers to understand, and communicate more effectively with, Chinese medical practitioners and will lead to greater acceptance of traditional medications in the West. Presenting a clear rationale for the use of traditional Chinese medications in Western medical facilities, the title enables scientists to find new directions in experimental design and encourage examination of these useful, but often poorly understood, preparations in clinical trials.