Daidoruijuho (大同類聚方)

Daidoruijuho was a unique Koiho (school of ancient medicine) document compiled in Japan in 808 during the early Heian period, while it was also the oldest government-designated pharmacopoeia. There are one hundred volumes in total.

Concerned about the possibility of Koiho being taken over by Chinese medicine, Emperor Heizei made a request to shrines, powerful local ruling families and old families in each province to submit their own Koiho that had been passed down through generations. The Emperor then requested ABE no Manao and IZUMO no Hirosada to classify and compile them. According to "Nihonkoki" (Later Chronicle of Japan), completion of the classification and compilation was reported to the Emperor on June 4, 808. The 'Daidoishiki' (detailed regulations on the use of the Daidoruijuho) was established in the same year and the prescription of medicines was required to follow its regulations.

During the Edo period, when Waho Igaku (ancient Japanese medicine) became an active area of study along with the promotion of the study of Japanese classical literature, the Daidoruijuho was treated as a sacred textbook for Wahoka (doctors in ancient Japanese medicine). In later years, however, a hypothesis appeared arguing that the books circulated at that time may have been forgeries. Since then there has been a controversy about the books even among the Wahoka, such as Naosuke GONDA who claimed that they were authentic, and Hojo SATO who argued that they were forged. From the modern age, however, Yu FUJIKAWA and others have supported the theory suggested by Hojo SATO. As a result, the prevailing opinion today is that the existing books are all forgeries and the real books were scattered and lost.

Worthy of note, however, is that the information in the existing books is accurate. The classical medicine researcher Sachiko MAKI is famous as the translator and interpreter for the entire Daidoruijuho.