Chaihu Guizhi Ganjiang is a 1,850 year-old formula that first appeared in Zhang Zhongjing’s classical formula primer, Treatise on Disorders Caused by Cold (Shanghan lun). In China, it is used to a much lesser degree than its two parent formulas, Xiao Chaihu Tang and Guizhi Tang. In Japan, however, it is considered to be an important item in the national pharmacopeia and prescribed for a wide variety of disorders. Japanese physicians emphasize that Chaihu Guizhi Ganjiang Tang is primarily indicated for patients with weak constitutions. More specifically, it can be said that this formula is suitable for shaoyang conditions complicated by damage to both body fluids and yang qi.