1-(2-methoxyphenyl)piperazine is an effective blocker of striatal dopaminergic receptors in rat brain and is apparently the simplest chemical structure known to exert dopaminergic blocking activity. It is exhibited pronounced antihypertensive and weak sympatholytic activities in experimental animals. Blood pressure was also lowered in hypertensive patients and this effect was sometimes accompanied by a strong sedation, and after large repeated doses, by disorientation and stupor. In a filter paper bioassay 1-(2-methoxyphenyl)piperazine demonstrated acaricidal activity. 1-(2-methoxyphenyl)piperazine is a building block of many serotonergic and dopaminergic agents. Some of them have antidepressant activity.