Wuxing, usually translated as Five Phases or Five Agents, is a fivefold conceptual scheme used in many traditional Chinese fields of study to explain a wide array of phenomena, including cosmic cycles, the interactions between internal organs, the succession of political regimes, and the properties of herbal medicines.

Chinese herbology is the theory of traditional Chinese herbal therapy, which accounts for the majority of treatments in traditional Chinese medicine (TCM). A Nature editorial described TCM as "fraught with pseudoscience", and said that the most obvious reason why it has not delivered many cures is that the majority of its treatments have no logical mechanism of action.