Shu Di Huang, the root of nine steamings

Shu Di Huang reads “cooked yellow of the earth”. Di Huang, the yellow of the earth, owes its name to the fresh root, an orange-yellow; the first character says what has been done to it. The root of Rehmannia glutinosa is mixed with yellow rice wine, then steamed and sun-dried, again and again: tradition speaks of nine steamings and nine dryings. It comes out black to the core, glossy, supple and sticky. Its reference growing region is Henan, around Jiaozuo, the former prefecture of Huaiqing, where it counts among the “four great herbs of Huai”. Under the Ming, one physician used it so much that he was nicknamed “Rehmannia Zhang”.

Nourishing the Blood, the Yin and the Essence

In traditional Chinese medicine, prepared rehmannia is slightly warm and sweet. The sweet taste tonifies, and this is one of the heaviest sweet herbs in the pharmacopoeia: dense and sticky, it descends and nourishes in depth. It enters the Liver, which stores the Blood, and the Kidney, which stores the Essence; tradition says these two Organs share the same source. This makes it the foremost herb for nourishing the Blood and the Kidney Yin: it provides the substance from which Blood is rebuilt, nourishes the Yin without coldness and descends to the deepest reserves of the Essence.

Raw or cooked: one root, two natures

Dried raw, the same root gives Sheng Di Huang, cold and bitter, which cools the Blood. Cooking changes everything: cold becomes slightly warm, bitter becomes sweet, and the clearing action gives way to a nourishing one. Its richness has a downside, which can weigh on a weak digestion; tradition therefore pairs it with herbs that promote movement, such as amomum or tangerine peel. With Chinese angelica, it forms the central pair of Si Wu Tang: one builds, the other sets in motion. Modern research is notably interested in catalpol.

Key benefits

Nourished Blood & deep resources

Sweet and dense, it provides the substance from which Blood is rebuilt, and nourishes the deep resources of Yin and Blood.

Kidney & Liver Yin

According to Chinese tradition, it nourishes the Kidney and Liver Yin, without the coldness of the raw root.

Essence & deep reserves

Heavy and sticky, it descends to the Kidney, which stores the Essence, the Jing, which it increases according to tradition.