N-Desmethylclozapine is a bioactive metabolite of clozapine, functioning as a potent 5-HT2C receptor antagonist (IC50: 7.1 nM), a dopamine D4 receptor antagonist, and a δ-opioid receptor agonist. It is a valuable research tool for investigating neuropsychiatric disorders and receptor pharmacology in both in vitro and in vivo experimental models.