Si shen tang, often called "4 Herbs Soup", is a preparation made of four Chinese medicinal plants: Shan yao (Chinese yam), Fu ling (Poria), Lian zi (lotus seeds) and Qian shi (spiny water lily seeds).

In traditional Chinese medicine, its use is recommended to drive out the Dampness which hinders the Spleen and the Large Intestine and which is thus at the origin of digestive disorders. Thus, by eliminating Dampness and strengthening the Spleen, Si shen tang improves the digestive system and stimulates the appetite.