The main ingredient of Mecobalamin Injection is vitamin B12, which can nourish the nerves and is commonly used in the treatment of peripheral neuropathy and macrocytic anemia caused by vitamin B12 deficiency. Usage and dosage of methylcobalamin injection is usually 0.5mg once, three times a week, for intramuscular injection or intravenous injection. Methylcobalamin Needle is used in the same way for the treatment of peripheral neuropathy and megaloblastic anemia, by intramuscular or intravenous injection, with a dosage of one injection, one 0.5mg, once a day, three times a week. It may be increased or decreased at the discretion of the physician in accordance with age and symptoms. After about two months of administration, one 0.5mg may be given every 1-3 months as maintenance therapy. Common adverse reactions to methylcobalamin injection are allergic reactions such as drop in blood pressure and difficulty in breathing; if these adverse reactions occur, the medication should be discontinued and appropriate measures should be taken. It should be noted that methylcobalamin injection is a prescription drug, and it should be used under the guidance of a doctor and a licensed pharmacist to ensure the safety of the drug.