Lysergic acid diethylamide, commonly known as LSD, is an illegal drug that alters the senses and cause hallucinations.
It was first synthesized in 1938 by a Swiss chemist, Albert Hofman, to treat respiratory depression. In 1943, Hofman accidentally discovered its hallucinogenic properties when he absorbed some through his skin.
Psychedelic drugs, also known as hallucinogenic drugs or simply hallucinogens, are a group of substances that are usually used recreationally to change and enhance sensory perceptions, thought processes, and energy levels, and to facilitate spiritual experiences. They include chemicals, such as LSD, and plants, such as peyote.1