Clozapine (HF 1854) dihydrochloride is utilized for researching psychiatric disorders. This compound exhibits high affinity for numerous neuroreceptors and acts as an effective antagonist of dopamine receptors, with a Ki value of 75 nM. Clozapine inhibits the muscarinic M1 receptor and serotonin 5HT2A receptor, with Ki values of 9.5 nM and 4 nM, respectively. Additionally, Clozapine is a selective agonist of the muscarinic M4 receptor (EC50 = 11 nM).