Da Chaihu Tang has the efficacy of detoxifying heat and dispersing knots, reconciling Shaoyang (treating exogenous heat illnesses in which the evil is between the half-expression and half-li), and clearing stomach fire, but does not have the efficacy of dispelling dampness. Da Chaihu Tang is one of the representative formulas for resolving the surface and attacking the interior, which is composed of Chaihu, Scutellaria baicalensis, Pinelliae, Paeoniae alba, Rhubarb, Citrus aurantium, Jujubae, and Ginger, and it has the effect of resolving the Shao-Yang and dispersing heat and knots. Da Chai Hu Tang can be used in the treatment of symptoms such as cold and heat exchanges (the body is hot and cold at the same time), bitter fullness in the chest and hypochondrium (feeling fullness and discomfort in front and at the sides of the chest), vomiting, constipation and so on. The adverse effects of this formula are not clear. In conclusion, according to the efficacy and main treatment of Da Chai Hu Tang, this formula can clear stomach fire but does not have the efficacy of dispelling dampness. Before using Da Chai Hu Tang, it is recommended to go to a regular hospital for consultation and treatment under the guidance of a professional physician.