Herbal therapy, next to dietary therapy, is perhaps the most widely used Traditional Chinese Medicine  (TCM) treatment modality. TCM relies on herbal therapies both for the treatment of illness and in the optimization of health and prevention of disease.
There are 5,767 medicinal substances currently in use, including plant, animal, and mineral substances. The materia medica (book on TCM medicinal substances) includes information on the traditional uses, dosages, and contra-indications for each substance, as well as any available information on drug interactions, and any conventional medical research that has been published.
TCM assesses medicinal substances for their effects on particular vital substances, their resonance with particular zang fu organ systems, the channels of the jing luo system into which the substance is said to enter, and the pathogenic factors and patterns of disharmony that the substance is known to address.
TCM practitioners most often use two or more substances in Chinese medicinal formulations to create a balanced, synergistic effect that reflects the holistic nature of the diagnosis.
Although there are literally thousands of traditional herbal formulas for just about every condition imaginable, a formula is almost always modified by the TCM practitioner to suit the subtle nuances of the condition and constitution of the patient, making each formulation highly individualized.
Chinese medicinal formulations are prepared in a number of different ways: