[citation needed] It next appears in the literature in the 1970s when it was investigated as a potential antidepressant medication,[11] but rejected when research reported that BZP had amphetamine-like effects and was liable to abuse.

[20] BZP has been shown to have a mixed mechanism of action, acting on the serotonergic and dopaminergic receptor systems in a similar fashion to MDMA.

[21] BZP has a high affinity action at the alpha2-adrenoreceptor, it is an antagonist at the receptor, like yohimbine, which inhibits negative feedback, causing an increase in released noradrenaline.

[23] Another study[24] lists 1-Benzylpiperazine (BZP)'s Release DAT, NET, and SERT EC50s (i.e. a measure of potency for the release of neurotransmitters via BZP's affinity for the dopamine, norepinephrine, and serotonin transporters respectively--whereby those transporter are induced to shuttle neurotransmitters out of neurons and deposit them in the synaptic gap) as 175, 62, and 6050; for comparison, the values listed for d-amphetamine (25, 7, and 1765) and d-methamphetamine (25, 12, and 736) show a similar DAT:NET affinity ratio as well as minor SERT activity which suggests BZP possesses similar activity to the two aforementioned drugs (when dosed ~7x higher due to lower potency) rather than serotonergic substituted amphetamines like MDMA.

[15] A 2005 study has shown that mixtures of BZP with other piperazine drugs such as TFMPP share certain pharmacodynamic traits with MDMA.

[8] Anecdotal evidence from online sources claim tolerance to the central action of BZP will develop quickly.

[28] The majority of the toxic effects information came from a 2005 study that recorded all presentations associated with party pill use at the Emergency Department of Christchurch Hospital, New Zealand.

[31] The major side effects include dilated pupils, blurred vision, dryness of the mouth, extreme alertness, pruritus, confusion, agitation, tremor, extrapyramidal symptoms (dystonia, akathisia), headache, dizziness, anxiety, insomnia, vomiting, chest pain, hallucinations, paresthesia, tachycardia, hypertension, palpitations, collapse, hyperventilation, sweating, hyperthermia and problems with urine retention.

[8] A retrospective study carried out at an Auckland emergency department found that BZP presentations only made a minor contribution to their overdose database, with most cases not producing any significant toxicity.

[40] BZP is banned in Australia, Austria, Canada, Denmark, Estonia, France, Germany, Greece, Ireland, Italy, Japan, Malta, Poland, Sweden and the United States.

[16][41] BZP is not controlled under any UN convention, so the compounds themselves are legal throughout most of the world, although in most countries their use is restricted to pharmaceutical manufacturing and recreational use is unknown.

The risk assessment came about as the result of a joint Europol – EMCDDA report which concluded that BZP needs to be looked at in more detail.

The report was published in June 2007,[44] and concluded that the use of BZP can lead to medical problems even if the long effects are still unknown.

Taking this concession as a basis, the European Commission asked the Council to place BZP under control of the UN Convention on Psychotropic Substances.

[47] Based on the recommendation of the EACD, the New Zealand government passed legislation which placed BZP, along with other piperazine derivatives (TFMPP, mCPP, pFPP, MeOPP, and MBZP), into Class C of the Misuse of Drugs Act 1975.