Albert Hofmann was a Swiss chemist known for being the first to synthesize, ingest, and learn of the psychedelic effects of lysergic acid diethylamide (LSD). Hofmann's team also isolated, named and synthesized the principal psychedelic mushroom compounds psilocybin and psilocin. He authored more than 100 scientific articles and numerous books, including LSD: Mein Sorgenkind. In 2007, he shared first place with Tim Berners-Lee on a list of the 100 greatest living geniuses published by The Daily Telegraph newspaper.

Psychedelics are a subclass of hallucinogenic drugs whose primary effect is to trigger non-ordinary mental states and an apparent expansion of consciousness. Also referred to as classic hallucinogens or serotonergic hallucinogens, the term psychedelic is sometimes used more broadly to include various types of hallucinogens, such as those which are atypical or adjacent to psychedelia like salvia and MDMA, respectively.