Methylcobalamin is an endogenous coenzyme vitamin B12 found in blood and medullary fluid. It can promote nucleic acid-protein-fat metabolism through methyl conversion reactions. It is a coenzyme of methionine synthase, which converts homocysteine to methionine. It can promote nucleic acid and protein synthesis, intra-axonal transport and regeneration of axons as well as the formation of myelin sheaths, and prevent axonal degeneration. Mecobalamin is used for diabetic neuropathy, polyneuritis and other peripheral neuropathy, and megaloblastic anemia and other diseases. In the process of using the drug may lead to loss of appetite, nausea and vomiting, diarrhea, allergy and other adverse reactions; prohibited for people with allergic reactions to the ingredients of the drug. If you need methylcobalamin, it is recommended to consult and use it under the guidance of a professional physician, do not blindly take it on your own.