MeOPP

4-methoxyphenylpiperazine (Paraperazine, MeOPP, 4-MeOPP) is a piperazine derivative with stimulant effects which has been sold as an ingredient in "Party pills", initially in New Zealand and subsequently in other countries around the world.

MeOPP has been found in vitro to inhibit monoamine re-uptake and stimulate their release. This is a mechanism of action shared with drugs of abuse such as amphetamines, and MeOPP produces somewhat similar effects although it is much less potent and is thought to have relatively insignificant abuse potential. Piperazine derivatives such as TFMPP have also been shown to exert a major part of their mechanism of action as non-selective serotonin agonists, and MeOPP has also been demonstrated to act in this way. MeOPP is anecdotally said to induce significantly less anxiety than similar piperazines, and is usually taken at doses between 120 - 200mg. It does not produce prominent stimulant effects, but is instead said to be relaxing, however it is often mixed with stimulant piperazine derivatives such as BZP for a combined effect.