Lysergic acid diethylamide (LSD), a molecule with two chiral centers and four possible stereoisomers, may refer to:
LSD (d-LSD, (+)-LSD, or (5R,8R)-LSD) – the active stereoisomer and psychedelic drug Iso-LSD (d-iso-LSD, (+)-iso-LSD, or (5R-8S)-LSD) – an inactive stereoisomer l-LSD ((–)-LSD or (5S,8S)-LSD) – an inactive stereoisomer l-Iso-LSD ((–)-iso-LSD or (5S,8R)-iso-LSD) – an inactive stereoisomer
See also Substituted lysergamide