Lysergic acid diethylamide, colloquially known as "LSD" or "acid," is a potent psychedelic drug that was first synthesized by Albert Hoffman on November 16, 1938. Hoffman, a researcher for the pharmaceutical-chemical department of Sandoz Laboratories in Basel, Switzerland, synthesized the drug while researching lysergic acid derivatives. It was originally thought to be a mere respiratory and circulatory stimulant. Its psychedelic properties remained unknown until a chance occurrence five years later.
On April 16, 1943, Hoffman chose to reexamine LSD, which had sat largely forgotten. In the course of synthesizing a new batch, Hoffman accidentally ingested some of the drug, likely by rubbing his face. Hoffman's accident would change the course of history.
He described the effect as being
"... affected by a remarkable restlessness, combined with a slight dizziness. At home I lay down and sank into a not unpleasant intoxicatedlike condition, characterized by an extremely stimulated imagination. In a dreamlike state, with eyes closed (I found the daylight to be unpleasantly glaring), I perceived an uninterrupted stream of fantastic pictures, extraordinary shapes with intense, kaleidoscopic play of colors. After some two hours this condition faded away."
Three days after his first experience, he deliberately ingested 250 micrograms of LSD. A day named "Bicycle Day," as the onset occurred while Hoffman was riding his bicycle home. It was the first ever intentional LSD experience.
Hoffman remained an advocate for and personal user of the drug for the rest of his life, referring to it as a "sacred drug" in his memoir.
LSD had a profound cultural impact when it was popularized for recreational use during the 1960s. It left an obvious fingerprint on any art form it touched. Indeed, "psychedelia" is still the visual shorthand for the era.
LSD's reputation as a dangerous party drug has been softened in recent years, as a movement grows in scientific fields related to neurology and mental health that supports psychedelic drugs as having beneficial clinical applications under controlled settings.