Monoacylglycerol lipase (MAGL) is an enzyme primarily responsible for hydrolyzing monoacylglycerol (MAG) to produce free fatty acids and glycerol, crucially involved in lipid metabolism and energy balance. MAGL is expressed in various tissues, particularly highly enriched in the liver, brain, and adipose tissue. The enzyme influences inflammatory responses, pain perception, tumor growth, and metabolic diseases by regulating endocannabinoid signaling and lipid signaling pathways. The activity of MAGL is regulated by gene expression and post-translational modifications, and specific expression patterns and gene mutations may lead to metabolic abnormalities and diseases. MAGL inhibitors have emerged as potential drug targets for treating neurodegenerative diseases, cancer, and inflammation-related disorders.