There are no studies on the adverse effects of cinnamon bark, but it should be noted that using too much cinnamon bark may cause symptoms such as dry mouth and bitterness, mouth ulcers, yellow and red urine, and dry stools. Gui Pi has the effects of warming the middle and dispersing cold (dispersing cold by warming the spleen and stomach), regulating qi and relieving pain (relieving pain by unblocking qi). Cinnamon bark belongs to the family of camphoraceous plants Geranium cinnamon and Sichuan cinnamon, and belongs to the warm li medicine. Gui Pi enters the spleen meridian, stomach meridian, liver meridian and kidney meridian, and is sweet, pungent and warm in nature, with the efficacy of warming the middle and dispersing cold, regulating qi and relieving pain. It is used in the treatment of lumbar and knee soreness and cold pain, cold pain in the epigastric region (stomach and epigastric and abdominal cold pain), cold hernia and abdominal pain (acute abdominal pain caused by the deficiency of coldness of the internal organs and the feeling of coldness of the wind from the external world), vomiting and diarrhea, bloody diarrhea, paralytic pain of cold and dampness, intestinal wind, dysmenorrhea of stagnation and pain of bruises and swelling. The adverse effects and contraindications of this drug are not clear. It should be noted that cinnamon bark used in excess may appear dry mouth and bitter mouth, mouth ulcers, yellowish red urine, dry stools and other symptoms. If necessary, please use under the guidance of a professional Chinese medicine practitioner.