HU-308 is a synthetic cannabinoid derivative with the chemical name ((4R)-4-(2,6-Dimethoxy-4-(2-methyl-octan-2-yl)phenyl)-6,6-dimethyl-bicyclo[3.1.1]hept-2-en-2-yl)methanol. It is structurally based on the bicyclic core of Δ9-tetrahydrocannabinol (THC) but is specifically designed as a highly selective agonist for the cannabinoid receptor type 2 (CB2). This compound is a potent and selective CB2 receptor agonist, exhibiting over 1000-fold selectivity for CB2 over the CB1 receptor. It is widely used in preclinical research as a pharmacological tool to study the role of the CB2 receptor in various physiological and pathological processes. Its primary applications are in neuroscience and immunology research, particularly for investigating neuroinflammation, neuropathic pain, and immune modulation, without the psychoactive effects associated with CB1 activation. HU-308 is considered a valuable research chemical for exploring the therapeutic potential of targeting the endocannabinoid system. It is not approved for human therapeutic use but serves as a key compound in drug discovery efforts aimed at developing novel analgesics and anti-inflammatory agents.