This chapter focuses on the formula for the entries of medicinal substances. It provides following information about the medicinal substances: 1) English name: Synonymous, scientific name, Arabic name. 2) Description and history. 3) PU: Practical uses. 4) TU: Theoretical uses, taken from medicine and pharmacy books and notebooks found in the Genizah. These were the professional literature that the physicians as well as the pharmacists used. 5) OMU: other medieval medicinal uses. 6) TM: traditional uses recorded among the inhabitants of different geographic areas and various ethnic groups in the Middle East. 6) TAI: trade, agriculture, and industry.Keywords:Genizah; materia medica; medicinal substances; medieval medicinal uses; pharmacists; physicians; practical uses; theoretical uses