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Alcohol, Tobacco, and Other Drugs

What is LSD?

The United States Drug Enforcement Administration considers LSD (lysergic acid diethylamide) the "most potent hallucinogen known to science." It is believed that LSD acts on certain groups of serotonin receptors in the cerebral cortex (effecting mood, cognition, and perception) and the locus ceruleus (effecting sensory signals received from the rest of the body). LSD is abused for the suspension of reality that it causes. Users may experience distorted perceptions of objects, movements, color, sound, touch, and body image—they often think they can fly. Users refer to these experiences a "trip," which can last up to 12 hours and be positive or negative based on the hallucinations the individual has—some hallucinations can be terrifying and cause panic. LSD is sometimes classified as a "club drug" because its effects make it popular among teenagers and young adults at bars, clubs, concerts, and parties.

LSD is typically taken orally in tablet, capsule, or blotter form. The liquid form is sometimes added to absorbent paper (blotter) that is divided into squares (each square is a dose) that are placed under the tongue.

Street names for LSD include acid and blotter.

What are the short-term consequences of using LSD?

The unpredictable effects of LSD begin to occur 30 to 90 minutes after taking the drug. Some initial physical reactions include dilated pupils, increased body temperature, increased heart rate and blood pressure, sweating, loss of appetite, sleeplessness, dry mouth, and tremors.

Rapid mood swings are often common. Hallucinations and delusions also occur if a large enough dose was taken. The experiences (the "trip") one has can last up to 12 hours. The trip one has is not always pleasant; some experience terrifying thoughts and feelings, fear of losing control, fear of insanity and death, and despair while using LSD. LSD intoxication has been implicated in some fatal accidents, sometimes resulting from a drug-induced belief that the individual can fly.

What are the long-term consequences of using LSD?

Some LSD users experience flashbacks of their experiences while under the influence of the drug that can occur more than a year after the person has taken LSD. LSD users may also develop long-lasting psychoses, such as schizophrenia or severe depression; but LSD's role in this manifestation is not well understood.

Is LSD addictive?

LSD is not considered an addictive drug because it does not produce compulsive drug-seeking behavior. LSD does, however, produce tolerance, meaning that a person must continuously increase their dosage to achieve the same effects.

Is LSD illegal?

LSD and its possession, use, sale, and manufacture are illegal.

Where can I get help?

Join Together, a project of the Boston University School of Public Health, maintains a searchable database on treatment facilities so that you can find one convenient to you. Visit and click on "Find Help."