There is no evidence of liver damage with the use of methylcobalamin. Methylcobalamin is a vitamin B₁₂ derivative that is commonly used clinically for the treatment of peripheral neuropathy and megaloblastic anemia due to vitamin B₁₂ deficiency. Common adverse reactions include lack of appetite, nausea, vomiting, and diarrhea. Adverse reactions to methylcobalamin do not include hepatic impairment, and there is no clinical evidence that methylcobalamin causes hepatic impairment. Methylcobalamin is contraindicated in patients with a history of hypersensitivity to methylcobalamin or any of the excipients in the drug. Although methylcobalamin is an over-the-counter medication, it should be taken under the supervision of a doctor and should not be taken on its own. If liver impairment occurs while taking methylcobalamin, it is recommended to seek medical attention to identify the cause.