Methylcobalamin should not normally be taken for long periods of time and should be discontinued after remission has been assessed by a doctor. If symptoms are not relieved after taking methylcobalamin for a month, it is usually necessary to stop taking it and consult a doctor. Methylcobalamin’s main effect is to nourish the nerves and can treat numbness in the hands and feet caused by neuritis. It can be used to relieve trigeminal neuralgia, diabetic peripheral neuropathy, polyneuritis, cerebrovascular accidents and other diseases, and can also be used for the sequelae of neuralgia caused by shingles. It should be noted that it is prohibited for those who are allergic to methylcobalamin. If during the use of methylcobalamin, allergic reactions such as rash, urticaria or gastrointestinal adverse reactions such as nausea and vomiting occur, patients are advised to stop using it immediately and go to the hospital in time. Methylcobalamin should be taken under the guidance of a doctor, and should not be used privately to avoid serious consequences.