The Multifaceted Du (毒): Practitioners’ Understanding and Clinical Applications in Traditional Chinese Medicine

Abstract Du (毒) commonly denotes poison and toxicity, carrying a negative connotation of harm in modern Chinese. However, within traditional Chinese medicine (TCM), Du possesses more diverse connotations. Through the examination of historical scholar-physicians’ works and semi-structured interviews with modern TCM practitioners, this research argues that Du should be understood in a relational way rather than merely as an intrinsic property of substances. From medical practitioners’ perspective, Du emerges from the interaction between substances and the human body. Firstly, substances that induce strong and undesired bodily sensations can be categorised as Du , denoting both potency and potential harm. Secondly, Du has also been interpreted as Pian Xing (偏性 imbalanced qualities of materia medica), referring to medicine’s qi (气 property) and Wei (味 flavour). These qualities, determined through sensory perceptions such as taste and smell, are the source of both therapeutic efficacy and potential harm if misused. Thus, in this context, the concept of Du does not inherently carry positive or negative connotations. Thirdly, when practitioners use Du to denote harm, this harm is generated from dynamic interplay among medicines, formulas, practitioners and patients. The interaction between these factors determines whether medicines will cause harm, rather than any inherent quality of the medicines themselves. However, influenced by modern science, the focus has shifted to isolated toxic components, moving away from the holistic emphasis on the lived body’s experiences. This shift has also influenced practitioners’ clinical use of Du -possessing medicines, which are regarded as toxic medicines.