What medicine is that?

You ask too many questions! ! I can only answer your Taoist alchemy.

In Taoist alchemy, the method of alchemy of human elements is called "then alchemy", also known as "yin and yang" The "yin and yang" referred to here actually refers to the yin and yang inside the human body, such as Shan Jingyun: "My husband and wife have contacts." That's what it means. It's not the so-called sexual intercourse between men and women that blind teachers and common people confuse people and promote obscenity. Like Tianyuan Danfa, it belongs to the Qing Dynasty. The so-called "then" refers to the formation of a golden air mass the size of an egg in the body, so it is called. The alchemy of "then" is the body of pure yang and lives as a "fairy".

Then it is formed by the essence, qi and spirit in the body.