CB1 receptor

Class

Cannabinoid receptor type 1 (CB1) inverse agonist/antagonist

The CB1 receptor is a G protein-coupled receptor that forms the core of the endocannabinoid system, a signaling network that uses lipid-derived messengers (endocannabinoids) to regulate appetite, energy balance, mood, and gastrointestinal and metabolic function. CB1 is densely expressed in the brain, particularly in regions governing feeding behavior and reward, but is also found in peripheral tissues such as adipose tissue, liver, pancreas, and gut. Chronic overactivation of this receptor has been linked to excess food intake, altered fat and glucose handling, and metabolic dysfunction. Inverse agonists and antagonists block or reduce baseline CB1 signaling, which can suppress appetite and improve metabolic parameters such as lipid and glucose handling. A major challenge with this mechanism is that blocking CB1 in the brain can also disturb mood and anxiety regulation, since the same receptor tone that influences eating also supports emotional stability. This has driven interest in compounds designed to act mainly outside the brain, or in antibody-based approaches that are less able to cross into the central nervous system, aiming to preserve peripheral metabolic benefits while minimizing central nervous system exposure. This mechanism is relevant to obesity, metabolic syndrome, and liver conditions involving fat accumulation.