Provided herein are methods of administering 4-methylpyrazole (4-MP), or physiologically acceptable salts thereof, to subjects of genetic subpopulations expressing specific polymorphisms of the alcohol dehydrogenase and aldehyde dehydrogenase genes. Also provided herein are methods to prevent or ameliorate ethanol intolerance, reduce or ameliorate symptoms associated with acetaldehyde accumulation accompanying ethanol consumption, or reduce the risk of diseases or disorders caused by consumption of ethanol, comprising administering 4-MP, or physiologically acceptable salts thereof, to subjects of these subpopulations.