1-(3-Chlorphenyl)piperazine (m-CPP), resulting from N-dealkylation of Trazodone, is a major circulating metabolite in humans. It is common to several antidepressants including Trazodone, Nefazodone, and Etoperidone. 1-(3-Chlorophenyl)piperazine is a SR-2C (5-HT2C)/SR-2B (5-HT2C) agonist/partial agonist and SR-2A (5-HT2A) antagonist.