Herbal medicine can be a powerful adjunctive therapy to other treatments. Trained TCM practitioners have spent years learning how to use Chinese herbal medicine, drawing from the clinical experience of a long lineage of practitioners, from ancient times until now. It is estimated that 25% of Western pharmaceutical drugs contain plant extracts or active principles. In TCM, whole herbs contain constituents, like volatile oils and tannins, that have chemical activities in our bodies. Herbs used are the highest quality available and rigorously tested for quality.