Assessing hepatotoxicity involves a combination of biochemical tests, imaging studies, and sometimes liver biopsy. Serum levels of liver enzymes such as ALT (alanine aminotransferase) and AST (aspartate aminotransferase) are primary indicators of liver injury. Elevated levels suggest liver cell damage. Imaging, such as ultrasound or MRI, can identify structural changes in the liver. In some cases, a liver biopsy is necessary to determine the extent and type of liver damage.