14-Hydroxy-LSD
14-Hydroxy-LSD is a lysergamide and a metabolite of the psychedelic drug lysergic acid diethylamide. It is formed via aromatic hydroxylation at position 14 of the lysergic acid moiety and is subsequently excreted as a glucuronide conjugate.
14-Hydroxy-LSD is a major metabolite of LSD in rats and guinea pigs, where it is excreted predominantly as a glucuronide in bile and urine. In contrast, it appears only as a minor metabolite in rhesus monkeys and humans. Studies using human liver microsomes and urine samples have confirmed its presence in humans, but in low concentrations that are often below quantification limits.
The specific enzymes involved in the formation of hydroxylated LSD metabolites like 14-hydroxy-LSD remain unidentified. As of 2016, David E. Nichols noted that the pharmacology of hydroxylated LSD metabolites, including 14-hydroxy-LSD, had not been studied. Notably, 14-hydroxy-LSD does not induce LSD-like changes in the EEG of rabbits, in contrast to LSD and 13-hydroxy-LSD.
14-Hydroxy-LSD was first reported in the scientific literature by at least 1975.