The difference between methylcobalamin and ghrelin mainly involves drug composition, dosage form, efficacy, indications, adverse reactions, precautions for drug use and other aspects. 1. Composition: the former is mainly made of methylcobalamin, and the latter is made of a mixture of ferulic acid esters mainly made of cycloartanols. 2. Dosage form: the former is mainly in the form of tablets, capsules and injections; the latter is mainly in the form of tablets. 3. Effects: The former mainly promotes the synthesis of nucleic acids and proteins in brain cells and nerve cells; the latter mainly plays a sedative and sleep-aiding role through the regulation of autonomic dysfunction and endocrine balance disorders. 4. Indications: the former is suitable for the treatment of peripheral neuropathy; the latter is suitable for neurosis, premenstrual tension syndrome and menopausal syndrome patients to calm and help sleep. 5. Adverse reactions: the former adverse reactions include loss of appetite, nausea, vomiting, diarrhea, rash, etc.; the latter adverse reactions include fatigue, rash, breast swelling, excessive oil secretion, alopecia, gastric discomfort, nausea, vomiting, dry mouth, weight gain. 6. Precautions for use: the former is prohibited for those who have a history of allergy to methylcobalamin, and it is not recommended to take it in large quantities for a long period of time for those who are engaged in the work of mercury and mercury compounds; the latter is prohibited for those who are allergic to glutathione. The use of specific drugs should be carried out under the guidance of a specialist physician, not unauthorized use of drugs.