What are hallucinogens?
Hallucinogens, or psychedelics, are drugs that affect a person's perceptions, sensations, thinking, self-awareness, and emotions. Hallucinogens include such drugs as LSD, mescaline, psilocybin, and DMT. Some hallucinogens come from natural sources, such as mescaline from the peyote cactus. Others, such as LSD, are synthetic or manufactured.

PCP is sometimes considered an hallucinogen because it has some of the same effects. However, it does not fit easily into any one drug category because it also can relieve pain or act as a stimulant.

What is LSD?
LSD is manufactured from lysergic acid which is found in ergot, a fungus that grows on rye and other grains. LSD was discovered in 1938 and is one of the most potent mood-changing chemicals. It is odorless, colorless, and tasteless. LSD is sold on the street in tablets, capsules, or occasionally in liquid form. It is usually taken by mouth but sometimes is injected. Often it is added to absorbent paper, such as blotter paper, and divided into small decorated squares, with each square representing one dose.

What is mescaline?
Mescaline comes from the peyote cactus and although it is not as strong as LSD, its effects are similar. Mescaline is usually smoked or swallowed in the form of capsules or tablets.

What are some other psychedelic drugs?
Psilocybin comes from certain mushrooms. It is sold in tablet or capsule form so people can swallow it. The mushrooms themselves, fresh or dried, may be eaten. DMT is another psychedelic drug that acts like LSD. Its effects begin almost immediately and last for 30-60 minutes.

What are the effects of psychedelics like LSD?
The effects of psychedelics are unpredictable. It depends on the amount taken, the user's personality, mood, and expectations, and the surroundings in which the drug is used. Usually, the user feels the first effects of the drug 30-90 minutes after taking it. The physical effects include dilated pupils, higher body temperature, increased heart rate and blood pressure, sweating, loss of appetite, sleeplessness, dry mouth, and tremors.

Sensations and feelings change too. The user may feel several different emotions at once or swing rapidly from one emotion to another. The person's sense of time and self change. Sensations may seem to "cross over," giving the user the feeling of "hearing" colors and "seeing" sounds. All of these changes can be frightening and can cause panic.

What are "bad trips"?
Having a bad psychological reaction to LSD and similar drugs is common. The scary sensations may last a few minutes or several hours and be mildly frightening or terrifying. The user may experience panic, confusion, suspiciousness, anxiety, feelings of helplessness, and loss of control. Sometimes taking a hallucinogen such as LSD can unmask mental or emotional problems that were previously unknown to the user. Flashbacks, in which the person experiences a drug's effects without having to take the drug again, can occur.

What are the effects of heavy use?
Research has shown some changes in the mental functions of heavy users of LSD, but they are not present in all cases. Heavy users sometimes develop signs of organic brain damage, such as impaired memory and attention span, mental confusion, and difficulty with abstract thinking. These signs may be strong or they may be subtle. It is not yet known whether such mental changes are permanent or if they disappear when LSD use is stopped.

What is PCP?
PCP (phencyclidine) is most often called "angel dust." It was first developed as an anesthetic in the 1950s. However, it was taken off the market for human use because it sometimes caused hallucinations.

PCP is available in a number of forms. It can be a pure, white crystal-like powder, or a tablet or capsule. It can be swallowed, smoked, sniffed, or injected. PCP is sometimes sprinkled on marijuana or parsley and smoked.

Although PCP is illegal, it is easily manufactured. It is often sold as mescaline, THC, or other drugs. Sometimes it may not even be PCP, but a lethal by-product of the drug. Users can never be sure what they are buying since it is manufactured illegally.

What are the physical effects of PCP?
Effects depend on how much is taken, the way it is used, and the individual. Effects include increased heart rate and blood pressure, flushing, sweating, dizziness, and numbness. When large doses are taken, effects include drowsiness, convulsions, and coma. Taking large amounts of PCP can also cause death from repeated convulsions, heart and lung failure, or ruptured blood vessels in the brain.

Why is PCP dangerous?
PCP can produce violent or bizarre behavior in people who are not normally that way. This behavior can lead to death from drownings, burns, falls (sometimes from high places), and automobile accidents. Regular PCP use affects memory, perception, concentration, and judgment. Users may show signs of paranoia, fearfulness, and anxiety. During these times, some users may become aggressive while others may withdraw and have difficulty communicating. A temporary mental disturbance, or a disturbance of the user's thought processes (a PCP psychosis) may last for days or weeks. Long-term PCP users report memory and speech difficulties, as well as hearing voices or sounds which do not exist.

How do PCP users feel?
Users find it difficult to describe and predict the effects of the drug. For some users, PCP in small amounts acts as a stimulant, speeding up body functions. For many users, PCP changes how users see their own bodies and things around them. Speech, muscle coordination, and vision are affected; senses of touch and pain are dulled; and body movements are slowed. Time seems to "space out."

Source: National Institute on Drug Abuse, 1984

Go to FACT Sheet List

Division of Alcohol and Drug Abuse
1706 East Elm; P.O. Box 687
Jefferson City, Missouri 65102