Cinnamon is very hot and can cause fire when brewed for a long period of time. Cinnamon bark tea has the effect of inducing fire to return to the source (inhibit the fire of the kidneys to rise), dispersing cold and relieving pain, replenishing fire to help yang, and invigorating blood circulation and menstruation. Cinnamon belongs to the warm medicine, family for the camphor plant cinnamon dried bark. Cinnamon bark is also known as cinnamon. Cinnamon is pungent, sweet and hot. Cinnamon bark enters the kidney meridian, spleen meridian, heart meridian and liver meridian. Cinnamon bark has the effects of inducing fire to return to the source, dispersing cold and relieving pain, tonifying fire and assisting yang, and promoting blood circulation and menstruation. It has been used in the treatment of menorrhagia, impotence, peng dolphin (a condition in which the patient feels that Qi rushes up from the abdomen to the chest and throat), uterine coldness, cold hernia (a severe abdominal pain caused by coldness of the internal organs and a recurrence of wind-cold), cold pain in the lumbar region and knees, cold vomiting and diarrhea, asthma due to deficiency of the kidneys, cold pain in the heart and abdomen, redness of the eyes and sore throat, dizziness caused by deficiency of yang and menstrual pain, etc. The adverse effects of Gui Pi are not known. Adverse effects of Gui Pi are not clear. Caution is advised for those with bleeding tendency and pregnant women; should not be used with red stone resin. If necessary, please use under the guidance of a professional Chinese medicine practitioner.