The Zhouhou beiji fang 肘後備急方 (Emergency formulas to keep on hand) is a complex formulary that is given little attention in the broader worlds of Chinese medicine and literature. Initially compiled in the fourth century by the Daoist scholar, Ge Hong 葛洪, it was given the name Zhouhou jiucu 肘後救卒 ([Formulas for] resuscitation to keep on hand). Since its creation, the text has undergone numerous changes, updates, expansions, and revisions at the hands of Tao Hongjing 陶弘景, Yang Yongdao 楊用道, and other unnamed editors. As the text grew and changed, it became intertwined in the vast network of formularies that exist in Chinese medicine. Over the course of fifteen hundred years the text expanded and contracted until it was incorporated into the Daoist Canon published in 1445, as the Ge Xianweng Zhouhou beiji fang 葛仙翁肘後備急方 (Old Immortal Ge Hong’s Emergency formulas to keep on hand) which contains nearly two thousand formulas.

By tracing the history of the Zhouhou beiji fang and its relationship to other works found in the genre of medical formularies, we can better understand the development and importance of this text, but also how formularies, grow, change, and influence each other as they transmit medical knowledge across generations.