A Chinese medicine and culture study reexamines “Du (毒)” in traditional Chinese medicine

Public concern over the safety of Chinese herbal medicines has grown over the past decades, particularly following high-profile incidents involving toxic compounds such as aristolochic acid, which was linked to kidney damage and led to regulatory bans in multiple countries. These events reinforced a modern toxicological framework in which toxicity is defined by the presence of harmful chemical components.

However, in traditional Chinese medicine (TCM), this boundary is far less rigid. In TCM, Du serves as a classificatory criterion in the pharmacological system. In modern medicine, the word loosely translates to “toxic chemical compounds” and usually carries a strongly negative meaning, suggesting danger and harm. However, the concept of Du is far more complex and necessitates context-dependent understanding that challenges modern biomedical assumptions.

A new study by Binli Dai from University of Oxford, United Kingdom, assesses how Du has been described in classical Chinese medical texts and how it is understood by contemporary TCM practitioners. “The concept of Du emerges through the interaction between medicines, practitioners, and patients. Based on classical texts and practitioners’ experiences, Du is not just about poison and danger but also about potency, Pian Xing, and the clinical context in which medicines are used,” mentioned by Dai while talking about the work. The study was published in the Chinese Medicine and Culture journal on January 07, 2026.

The study aims to examine Du’s interpretations rationally, rather than treating it as an intrinsic and stable medicinal property. For this, the author examined foundational TCM-related textbooks, historical scholar-physicians’ notes, and semi-structured interviews with eight TCM practitioners.  The findings from textbooks revealed that medicines may or may not possess Du. However, medicines with Du were not necessarily avoided. On the contrary, they were often valued for their therapeutic efficacy and potency. In this sense, Du could signify potency as well as danger. These medicines were seen as capable of addressing more serious disorders because of their higher curative strength and therapeutic immediacy. The study highlights that this dichotomy of therapeutic power and harmful nature of Du possessing medicines necessitates a higher degree of cautiousness in medical practice. 

The paper also highlights another important interpretation of Du, its connection to Pian Xing, or the imbalanced qualities of medicinal substances. It is a neutral trait, and its advantageous or detrimental state depends on clinical application and context. This viewpoint highlights the negative effects of medication abuse. If medications are harmful, it is because of how they are used rather than solely being based on the inherent qualities of the substance. This necessitates a relational understanding of Du in TCM, which takes into account its effects in context as opposed to giving the substance alone fixed qualities.

Interviews with practitioners showed that this previously held understanding still survives, though it is increasingly shaped by modern biomedical thinking. Some practitioners continue to associate “Du” with therapeutic strength and clinical usefulness. Whereas, others now interpret it more narrowly as toxicity or harmfulness, especially under the influence of modern pharmacology and regulation. This shift has made many clinicians more cautious about prescribing medicines considered highly potent or potentially dangerous.

The study also highlighted the understanding of Du through three interrelated dimensions: the practitioner, the patient, and the materia medica. The findings drawn from the interviews—that while some clinicians still recognize the beneficial potency of Du-possessing medicines, many interpret it as harmful—necessitate greater caution in clinical practice. For most clinicians, Du is a relational phenomenon that emerges from inappropriate clinical practice and cannot be attributed to the medicinal substance alone.

The study also emphasizes patient health; socioeconomic background plays an important role in this context as they interact with the medicine. An herb that alleviates symptoms in one patient may cause adverse effects in another, depending on their physiological condition. 

The study also points out how TCM-related books like Materia medica emphasize pharmaceutical techniques that can modulate the Du of a medicine. The processing technique, also known as Pao Zhi, combines herbs into formulas and adjusts preparation methods, demonstrating how practitioners actively transform and control the effects of medicines. These practices aim to reduce potential harm while preserving therapeutic benefits, reinforcing the idea that Du is shaped by clinical context rather than fixed chemical properties.

The increasing dominance of regulatory frameworks based on biochemical toxicity has led to reduced use of potent medicines, even when they may be clinically effective. Rather than viewing toxicity as an inherent attribute, the study suggests that understanding how medicines are used may be key to balancing efficacy and safety in both traditional and modern healthcare systems.

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Reference
DOI: 10.1097/MC9.0000000000000174


About University of Oxford, United Kingdoms
University of Oxford is one of the world’s most renowned centers of learning, known for its long history, academic excellence, and global influence. Located in Oxford, England, the university is made up of a distinctive collegiate system that brings together students and scholars across a wide range of disciplines. Its teaching combines rigorous scholarship with close mentorship, fostering both intellectual depth and independent thinking. Oxford has contributed significantly to research, literature, medicine, public policy, and science over the centuries. With an international academic community and a strong tradition of innovation, it continues to shape education and research on a global scale.
Website: https://www.ox.ac.uk/

About Binli Dai from University of Oxford
Binli Dai is a D.Phil student in Anthropology at the School of Anthropology and Museum Ethnography, University of Oxford. Her current research centers on TCM, with a focus on the inheritance modes of contemporary TCM and the contemporary understanding and evolution of its core concepts. Meanwhile, keen interest is also devoted to other realms of traditional culture, including Tai Chi and ancient architecture.