The usual dosage of methylcobalamin injection is once a day, three times a week, but after it is used for the treatment of megaloblastic anemia and has been administered for about 2 months, it may be continued every 1 to 3 months. Methylcobalamin Injection’s main component, methylcobalamin, is an endogenous coenzyme B12, which is involved in the cycling of one-carbon units in the body; in addition, it can also promote the synthesis of nucleic acids and proteins in neuronal cells, and promote the maturation and division of orthoerythrocytic hemoblasts, etc. It is mainly used in the treatment of peripheral neuropathy. It is mainly used in the treatment of peripheral neuropathy and macrocytic anemia caused by vitamin B12 deficiency. As a peripheral neuropathy drug, it is recommended that adults use it 3 times a week, intramuscularly or intravenously; as a megaloblastic anemia drug, it is also recommended that adults use it 3 times a week, and after about 2 months of using the drug, it can be used once every 1 to 3 months to continue maintenance therapy. The drug is contraindicated in people who are allergic to the product, and prolonged and intensive use of the drug is not recommended for people involved in the work with mercury and mercury compounds. Adverse reactions such as nausea, loss of appetite, vomiting, diarrhea, skin rash may occur after use of the drug. Specific use of the drug should be carried out under the guidance of a specialist, and should not be used without authorization.