Hanaoka was intrigued when he learned about Hua Tuo's mafeisan potion. Beginning in about 1785, Hanaoka embarked on a quest to re-create a compound that would have pharmacologic properties similar to Hua Tuo's mafeisan. His wife, who participated in his experiments as a volunteer, lost her sight due to adverse side effects. After years of research and experimentation, he finally developed a formula which he named "tsūsensan" (also known as "mafutsu-san"). Like that of Hua Tuo, this compound was composed of extracts of several different plants, including: