The study reports the development of JZL184, a potent and selective inhibitor of monoacylglycerol lipase (MAGL), which is responsible for the enzymatic hydrolysis of 2-arachidonoylglycerol (2-AG), an endocannabinoid. Administration of JZL184 to mice significantly elevates brain 2-AG levels by 8-fold without affecting anandamide levels. This elevation in 2-AG leads to a broad array of CB1-dependent behavioral effects, including analgesia, hypothermia, and hypomotility, suggesting that 2-AG plays a significant role in modulating various behavioral processes associated with cannabinoids. The study also highlights the importance of distinguishing between the metabolic pathways of 2-AG and anandamide, as previous inhibitors of fatty acid amide hydrolase (FAAH) only partially affect 2-AG metabolism. JZL184's selectivity for MAGL over FAAH and other serine hydrolases makes it a valuable tool for studying endocannabinoid signaling in vivo. The compound's ability to elevate 2-AG levels and induce CB1-dependent behavioral effects underscores the role of 2-AG in endocannabinoid signaling and its potential as a therapeutic target. The study also demonstrates that JZL184 can be administered via multiple routes and maintains its efficacy over an extended period, making it a promising candidate for further pharmacological investigation.The study reports the development of JZL184, a potent and selective inhibitor of monoacylglycerol lipase (MAGL), which is responsible for the enzymatic hydrolysis of 2-arachidonoylglycerol (2-AG), an endocannabinoid. Administration of JZL184 to mice significantly elevates brain 2-AG levels by 8-fold without affecting anandamide levels. This elevation in 2-AG leads to a broad array of CB1-dependent behavioral effects, including analgesia, hypothermia, and hypomotility, suggesting that 2-AG plays a significant role in modulating various behavioral processes associated with cannabinoids. The study also highlights the importance of distinguishing between the metabolic pathways of 2-AG and anandamide, as previous inhibitors of fatty acid amide hydrolase (FAAH) only partially affect 2-AG metabolism. JZL184's selectivity for MAGL over FAAH and other serine hydrolases makes it a valuable tool for studying endocannabinoid signaling in vivo. The compound's ability to elevate 2-AG levels and induce CB1-dependent behavioral effects underscores the role of 2-AG in endocannabinoid signaling and its potential as a therapeutic target. The study also demonstrates that JZL184 can be administered via multiple routes and maintains its efficacy over an extended period, making it a promising candidate for further pharmacological investigation.