Methylcobalamin tablets are medications used for peripheral neuropathy and commonly have gastrointestinal reactions such as loss of appetite, nausea, vomiting and diarrhea as well as side effects such as rash hypersensitivity. Methylcobalamin Tablets can be used to treat a variety of peripheral nervous system disorders such as peripheral neuropathy, facial neuritis, including facial sensitivity, pain, numbness, tingling in hands and feet, muscle weakness, etc., and it has a nutritive effect on the nerves. The drug can also relieve to some extent the symptoms of dizziness, weakness, loss of appetite, symmetrical numbness of hands and feet, etc., which occur in patients with megaloblastic anemia. Common side effects of methylcobalamin mainly manifested as dyspepsia, nausea and vomiting, loss of appetite, diarrhea and abdominal pain and other gastrointestinal adverse reactions, the general reaction is relatively mild, does not affect the continuation of the medication, the reaction can be disappeared after discontinuation of the drug. Patients with allergies may experience more serious side effects such as skin rashes and diarrhea. Methylcobalamin is contraindicated in patients who are allergic to any of the excipients in the prescription. It should not be used in large quantities by those working with mercury and its compounds. Methylcobalamin tablets should be taken in accordance with the doctor’s instructions, and should not be used without authorization or change the dosage, so as not to cause adverse reactions.