Sun Buer is the only woman among the Seven Perfected and the tradition credits her with founding nüdan, the separate literature of womens internal alchemy, which differs from the male practice in its physiology — beginning with work on the breasts and the transformation of menstruation, described as slaying the red dragon. The most repeated story about her is that in order to travel and practise safely she deliberately disfigured herself, pouring hot oil on her face so that she could beg on the road without being molested; she is said to have been fifty-one when she left her family. The texts attributed to her are almost certainly later, in the manner of most such attributions, but the tradition of womens alchemy that carries her name is real and substantial, and Quanzhen has ordained women continuously, with women abbots at significant temples. Her presence is one of the reasons Quanzhen looks different from the hereditary priesthood, which passes through sons.