Some people consume pu-erh for its' purported medicinal properties. The Kunming Medical college claims that pu-erh lowers cholesterol and triglycerides (unsubstantiated). The leaves come from the Yunnan Dayeh tea bush, said to be related to the original tea bush of pre-glacial times. In production the leaves are picked, rolled, withered, and then steamed. Before drying they are pressed into cakes and then naturally dried. During drying, mold may develop which gives the tea a complex character. Pu-erh is then stored and aged. Like wine, the older the pu-erh, the more valuable it becomes.