Which school is Sanyuan Zhen Jing?

Sanyuan Zhen Jing is one of the classics of Taoist inner alchemy and belongs to the category of Taoist inner alchemy. In the history of China, Taoist Inner alchemy was once a relatively independent school, which complemented other schools of Taoism and Buddhism. Inner alchemy has a long history, and many famous schools and masters have emerged, such as Zhang Heng in Han Dynasty, Guo Pu in Jin Dynasty, Li Jing in Tang Dynasty and Lu Jiuyuan in Song Dynasty. Inner alchemy is a cultivation method in Taoism, aiming at strengthening the body, improving the spirit and prolonging life through spiritual, respiratory and physical cultivation. Compared with other schools of Taoism, such as Dantian School and Wuxing School, Sanyuan Zhen Jing advocates the cultivation method of "three-in-one".