Elixir of the Ultimate Medicine 还丹至药篇

Originally attributed to "Wuxuanzi (Enlightened Mystic), styled Xianzhi, given name Yingtutu" (Wuxuanzi Xianzhi Yingtutu Shu).

Consisting of one scroll, it is included in the Tai Xuan Section within the Taoist Canon (The Daozang).

Elixir of the Ultimate Medicine

According to the author’s preface at the beginning of the chapter, he claims his given name is Yingtutu, styled Xianzhi, and his Taoist title is Wuxuanzi. He practiced refining the "Five Metals and Eight Stones" (mineral medicines) for more than twenty years without success; later, he encountered a "Supreme Person" who imparted secret instructions to him, and only then did he witness the mystical powers. This chapter collects ten of his seven-character regulated poems, describing the hardships of cultivating the Dao, lamenting the rarity of true secret instructions, and praising the mystical efficacy of the Returning Elixir. It asserts that the Golden Elixir is based on true lead and true mercury.

Judging from his alchemical poems, the author was presumably from the Song Dynasty. History of the Song Dynasty·Treatise on Arts and Literature records two works by Wuxuanzi: One Scroll of Prescriptions for Calming the Spirit and Nurturing Nature and One Scroll of Secret Prescriptions in the Box. He is suspected to be the same person.