PCP, short for phencyclidine, is a powerful mind-altering drug that was originally developed as a surgical anesthetic in the 1950s. It belongs to a class of drugs called dissociative hallucinogens, meaning it distorts perception, creates feelings of detachment from reality, and can trigger vivid hallucinations. PCP is classified as a Schedule II controlled substance in the United States, placing it among drugs with a high potential for abuse.
How PCP Was Developed and Why It Was Abandoned
Pharmaceutical researchers created PCP in the 1950s because it could numb pain and induce anesthesia without significantly suppressing breathing or heart function, a major advantage over other anesthetics of the time. It was marketed under the brand name Sernyl and began seeing use in surgical procedures by 1963. Within just four years, doctors stopped using it on humans. The problem: patients waking up from PCP anesthesia frequently experienced intense confusion, disturbing hallucinations, and a state of distress called postoperative dysphoria. Ketamine was developed in 1963 specifically as a replacement, offering similar anesthetic properties with fewer psychological side effects.
By the early 1970s, PCP had migrated from operating rooms to the streets, gaining a reputation as a hallucinogen. It has remained an illicit drug ever since.
What PCP Does to the Brain
PCP works by blocking a specific type of receptor in the brain involved in learning, memory, and perception. Under normal conditions, these receptors help brain cells communicate using a chemical messenger called glutamate, which plays a central role in how you process information and coordinate thoughts. When PCP blocks this system, the brain’s signaling becomes chaotic. Neural activity within and between brain networks loses its coordination, which is why the drug produces such a wide range of unpredictable mental effects.
This disruption is also why PCP can mimic the symptoms of schizophrenia so closely. The connection was significant enough that researchers studying PCP helped shape the theory that schizophrenia itself may involve dysfunction in the same brain signaling pathways.
Forms, Street Names, and How It’s Used
PCP is sold as a powder, crystal, liquid, tablet, or capsule. The most common forms on the street are powder and liquid. Smoking is the most popular method of use. People typically soak leafy material like mint, parsley, oregano, tobacco, or marijuana in liquid PCP, then roll it into a cigarette and smoke it. A marijuana joint or regular cigarette dipped in liquid PCP is called a “dipper.”
PCP can also be snorted or swallowed. It goes by dozens of street names, including Angel Dust, Hog, Ozone, Rocket Fuel, Shermans, Wack, Crystal, and Embalming Fluid. When combined with marijuana, the mixture may be called Killer Joints, Super Grass, Fry, Lovelies, Wets, or Waters.
Effects at Different Doses
PCP’s effects vary dramatically depending on how much is taken, and the line between a “mild” dose and a dangerous one is thin.
At low doses (roughly 1 to 5 mg), PCP produces sedation and a loss of inhibitions. Users may experience slurred speech, an unsteady walk, a blank stare, and a rise in body temperature. Even at these lower amounts, violent behavior can occur. The drug creates a state sometimes described as dissociative anesthesia, where a person feels disconnected from their body and surroundings while also being physically numbed to pain.
At moderate doses (5 to 10 mg taken orally), the drug can trigger a state that closely resembles acute schizophrenia. This includes intense agitation, psychosis, hearing and seeing things that aren’t there, paranoid delusions, and catatonia, a condition where a person becomes unresponsive or locked into rigid postures. PCP is notorious for inducing feelings of euphoria, invincibility, and the illusion of superhuman strength, which partly explains why intoxicated individuals sometimes engage in dangerous or self-destructive behavior.
More than half of adults who arrive at emergency departments after taking PCP show a characteristic pattern: violent behavior, rapid heart rate, high blood pressure, numbness to pain, and a distinctive involuntary eye movement where the eyes jerk horizontally, vertically, or in a rotating pattern. Self-mutilation is one of the more disturbing behavioral effects associated with the drug.
Long-Term Effects on Thinking and Memory
Repeated PCP use takes a measurable toll on the brain. Research in animal models shows that PCP disrupts how groups of brain cells fire together in the hippocampus, a region essential for memory and spatial navigation. The drug impairs cognitive control, which is the ability to process information deliberately and work toward goals rather than acting on impulse. In practical terms, chronic users often struggle with memory, clear thinking, speech, and mood regulation.
A single dose produces effects that typically last about an hour in terms of measurable brain disruption. But with repeated exposure, the changes can become more persistent. The drug appears to alter the brain’s ability to strengthen or weaken connections between cells, a process that underlies learning and memory formation. This means the cognitive damage from long-term use may outlast the high by a significant margin.
How Long PCP Stays in Your System
PCP is detectable in the body well after its effects wear off. Standard urine tests can pick it up for 5 to 6 days after use, though some tests extend that window to about 8 days. Sweat-based testing detects PCP for 7 to 14 days. Hair tests have the longest window at up to 90 days, making them useful for identifying patterns of use over time rather than a single recent dose.
How Common PCP Use Is Today
PCP use is relatively uncommon compared to other illicit drugs, but it hasn’t disappeared. Federal survey data from 2023 found that 3.1% of Americans aged 12 or older (about 8.8 million people) used some type of hallucinogen in the past year, a category that includes PCP alongside LSD, psilocybin mushrooms, MDMA, ketamine, and others. Young adults aged 18 to 25 had the highest rate at 6.7%. PCP-specific numbers are harder to isolate from these broader figures, but researchers have noted that PCP abuse has been increasing in frequency in recent years.
Risks of Overdose
PCP overdose is a medical emergency. Because the drug numbs pain and distorts judgment simultaneously, people under its influence may not recognize injuries they’ve sustained or understand the danger they’re in. High doses can cause seizures, dangerously elevated body temperature, severe spikes in blood pressure, and loss of consciousness. The combination of physical numbness, extreme agitation, and impaired decision-making makes PCP intoxication uniquely hazardous, both to the person who took it and to anyone nearby. There is no antidote for PCP. Emergency treatment focuses on managing symptoms, keeping the person safe, and preventing complications until the drug clears the system.