Methylcobalamin tablets are recommended to be taken continuously for about 1 month. If the patient takes methylcobalamin tablets for more than 1 month and there is no obvious effect, the patient is recommended to stop using methylcobalamin. Methylcobalamin is endogenous vitamin B12, which can play the role of nerve nutrition. It is mainly for the treatment of peripheral neuropathy, such as diabetic peripheral neuropathy, alcoholic peripheral neuropathy, as well as carpal tunnel syndrome and elbow tunnel syndrome resulting in damage to the ulnar nerve and median nerve, patients can be given with oral methylcobalamin, and patients with peripheral facial neuritis can also take methylcobalamin orally.2. It is recommended that patients take methylcobalamin orally for one month, and individual patients taking methylcobalamin can experience abdominal distension and The symptoms of indigestion can be tolerated after about 3-5 days. If the clinical symptoms are improved to a certain extent after taking methylcobalamin, the time of oral administration can be extended appropriately under the guidance of physicians to about half a month. If necessary, liver and kidney function tests as well as the determination of vitamin B12 in serum should be carried out.