Lysergsäurediethylamid - from ergots to revelation via hydrazinolysis.

LSD, or lysergic acid diethylamide, is a potent psychedelic compound derived from lysergic acid, a molecule associated with ergot fungi. Its molecular formula is C₂₀H₂₅N₃O, and its structure contains an indole ring system related to serotonin. LSD binds strongly to several serotonin receptors, especially 5-HT_2A receptors, altering signaling in brain networks involved in perception, cognition, and mood. Extremely small quantities can produce pronounced effects because of its high receptor affinity and potency. The molecule is chiral, and only one stereoisomer has strong psychedelic activity. LSD is used primarily in neuroscience, pharmacology, psychiatric research, and studies of human consciousness and perception.