Chai Hu Gui Zhi Tang, a combined formula of Xiao Chai Hu Tang and Gui Zhi Tang, was originally designed to treat concurrent Tai Yang (Great Yang) and Shao Yang (Lesser Yang) syndromes. It possesses both the function of harmonizing and resolving Shao Yang while also releasing the muscle layer to expel the Exterior pathogen, making it effective for treating diseases involving both the Tai Yang and Shao Yang channels.

Additionally, it can harmonize the Nutritive and Defensive levels and regulate Qi and Blood internally, thus treating various internal and external conditions where the channels of 4 levels (Nutritive, Defensive, Qi and Blood) are obstructed.

Clinically, it is often used to treat conditions with concurrent Tai Yang and Shao Yang involvement, such as fever, cough, asthma, chest and hypochondriac pain, epigastric pain, vomiting, arthralgia, and edema. There are also reports of its use in treating epilepsy, nocturnal enuresis, cholelithiasis (gallstones), cholecystitis, hepatitis, pancreatitis, vertigo, pleurisy, intercostal neuralgia, gastric and duodenal ulcers, acute pyelonephritis, mild epidemic hemorrhagic fever, chronic sinusitis, urticaria (hives), postpartum fever, fever of unknown origin, pediatric orthostatic dysregulation, and pediatric anorexia, especially in cases involving both Shao Yang and Tai Yang patterns.