Phencyclidine or phenylcyclohexyl piperidine (PCP), also known in its use as a street drug as angel dust among other names, is a dissociative anesthetic mainly used recreationally for its significant mind-altering effects.

Low doses produce numbness in the extremities and intoxication, characterized by staggering, unsteady gait, slurred speech, bloodshot eyes, and loss of balance.

[15] The drug is often illegally produced under poorly controlled conditions; this means that users may be unaware of the actual dose they are taking.

[16] Psychological effects include severe changes in body image, loss of ego boundaries, paranoia, and depersonalization.

Psychosis, agitation and dysphoria, hallucinations, blurred vision, euphoria, and suicidal impulses are also reported, as well as occasional aggressive behavior.

[17][18]: 48–49 [15] Like many other drugs, PCP has been known to alter mood states unpredictably, causing some individuals to become detached, and others to become animated.

[18]: 48  Although uncommon, events of PCP-intoxicated individuals acting in an unpredictable fashion, possibly driven by their delusions or hallucinations, have been publicized.

[20][21] Recreational doses of the drug also occasionally appear to induce a psychotic state, with emotional and cognitive impairment that resembles a schizophrenic episode.

[3] PCP's rewarding and reinforcing effects are at least partly mediated by blocking the NMDA receptors in the glutamatergic inputs to D1-type medium spiny neurons in the nucleus accumbens.

[27] A 2019 review found that the transition rate from a diagnosis of hallucinogen-induced psychosis (which included PCP) to that of schizophrenia was 26%.

PCP can also be orally ingested, injected subcutaneously or intravenously, or smoked laced with marijuana or cigarettes.

[29] Management of PCP intoxication mostly consists of supportive care – controlling breathing, circulation, and body temperature – and, in the early stages, treating psychiatric symptoms.

Typical antipsychotics such as phenothiazines and haloperidol have been used to control psychotic symptoms, but may produce many undesirable side effects – such as dystonia – and their use is therefore no longer preferred; phenothiazines are particularly risky, as they may lower the seizure threshold, worsen hyperthermia, and boost the anticholinergic effects of PCP.

The role of NMDAR antagonism in the effect of PCP, ketamine, and related dissociative agents was first published in the early 1980s by David Lodge[47] and colleagues.

[53] Findings demonstrate that presynaptic nAChRs and NMDA receptor interactions influence the postsynaptic maturation of glutamatergic synapses and consequently impact synaptic development and plasticity in the brain.

[39] Studies on rats indicate that PCP interacts indirectly with opioid receptors (endorphin and enkephalin) to produce analgesia.

[65] Some studies found that, like other NMDA receptor antagonists, PCP can cause a kind of brain damage called Olney's lesions in rats.

[73][74] Phencyclidine was initially discovered in 1926 by Arthur Kötz [de] and his student Paul Merkel as a product of a Grignard reaction of 1-piperidinocyclohexancarbonitrile.

[75] It was again synthesized in 1956 by chemist H Victor Maddox and brought to market as an anesthetic medication by pharmaceutical company Parke-Davis, now a subsidiary of Pfizer.

[7] In 1978, People magazine and Mike Wallace of the TV news program 60 Minutes called PCP the country's "number one drug problem".

[82] Tsukasa Hojo's 1985 manga City Hunter features a drug, Angel Dust, presumably a reference to PCP's street name.

The related 2023 animated film, City Hunter: Angel Dust, more directly moved the franchise's angel dust into the realm of fantasy, as it is portrayed as a science fiction nanomachine serum developed by a biotech company to create super-soldiers with a tendency to drive them berserk, side-stepping the real-life PCP.