Metachlorophenylpiperazine (mCPP) is a psychoactive substance that appeared in 2004 on the black market of illicit substances in Europe and France. It has a strong affinity for serotoninergic receptors and the serotonin transporter. In humans, mCPP induces endocrine, neurological and psychiatric effects. Its subjective effects are similar to those of amphetamines. However, drug-users allot few positive subjective effects. Reported cases of intoxication are generally not serious but the risks of psychiatric disorders and serotoninergic syndrome must be taken into account. Risk factors of the intoxication to mCPP are the existence of predisposing psychiatric pathologies and pharmacodynamic or metabolic interactions. mCPP does not exhibit reinforcing effects. mCPP is not the subject of any international regulation: procedures of medical and social risk assessment were implemented in European and the national levels.