The dosage requirement for Chai Hu is between 3 to 10 grams. Chaihu is a traditional Chinese medicine and is the dried root of Chaihu or Narrow-leaved Chaihu of the Umbelliferae family. It has a bitter, pungent flavor, is slightly cold in nature, and belongs to the liver, gallbladder and lung meridians. Chaihu is effective in evacuating and reducing fever, relieving the liver and resolving depression (treating depression by unblocking liver qi), and elevating yang qi. It can be used in the treatment of cold and fever, cold and heat (the body is hot and cold at the same time), liver depression and stagnation of qi (the liver’s qi and blood circulation is not smooth, emotional depression), distension and pain in the chest and ribs, menstrual disorders, uterine prolapse, prolapse of the anus, and other disorders. The adverse effects of Chai Hu are not clear. Its nature is ascending and dispersing, so it is contraindicated or used with caution in cases of yin deficiency and hyperactivity of yang (deficiency of yin fluid and hyperactivity of yang qi), internal movement of liver wind, yin deficiency and hyperactivity of fire (deficiency of yin essence in the body and hyperactivity of deficiency fire), and qi upward reversal. Its regular dosage is 3~10 grams, so it should not be used in excess of the dosage for a long period of time. Chai Hu should be used by a professional Chinese medicine practitioner after diagnosis, and should not be used blindly on its own to avoid aggravation of the condition or adverse reactions.