12-Methoxy-LSD

12-Methoxy-LSD, also known as 12-methoxylysergic acid diethylamide, is a drug of the ergoline and lysergamide families and a derivative of lysergic acid diethylamide (LSD). In terms of chemical structure, 12-methoxy-LSD is to LSD as 5-MeO-DMT is to dimethyltryptamine (DMT), with 12-methoxy-LSD notably containing 5-MeO-DMT within its conformationally constrained structure. Both 12-methoxy-LSD and its analogue 12-hydroxy-LSD have been described as non-hallucinogenic in humans. However, in other more recent reports, 12-hydroxy-LSD produced psychedelic-like effects in rodents and was said to have similar activity as LSD in humans.

It has been reported that 12-methoxy-LSD does not produce hallucinogenic effects in humans. However, it is nonetheless pharmacologically active in animal studies. The drug's effects in rabbits include antiserotonergic activity (20% of that of LSD) and hyperthermia (dose ratio relative to LD50Tooltip median lethal dose of 1:17 for 12-methoxy-LSD and 1:725 for LSD). In addition, like LSD, it is highly potent in terms of lethality, with a median lethal dose (LD50) of 0.1 mg/kg i.v.Tooltip intravenous administration in rabbits (relative to 0.1 mg/kg for LSD). 12-Methoxy-LSD also produces LSD-like electroencephalogram (EEG) changes in rabbits.

Presumably 12-methoxy-LSD acts as an agonist of serotonin and dopamine receptors, as with LSD and other related lysergamides, but its pharmacology has not been studied with modern techniques.

The chemical synthesis of 12-substituted lysergamides is described as being very difficult.

An analogue of 12-methoxy-LSD is 12-hydroxy-LSD, which would be structurally akin to bufotenin (5-HO-DMT). As with 12-methoxy-LSD, it has been reported that 12-hydroxy-LSD is inactive as a psychedelic in humans. Contrary to this report however, Michael Valentine Smith claimed in his 1981 book Psychedelic Chemistry that 12-hydroxy-LSD has "about the same activity as LSD". In addition, 12-hydroxy-LSD has been found to substitute for LSD in rodent drug discrimination tests with about 20% of its potency.

12-Methoxy-LSD was first described in the scientific literature by 1967. Subsequently, it was further described in the 1970s and 1980s.

• Substituted lysergamide

• 12-Hydroxy-LSD

• 13-Methoxy-LSD

• 14-Methoxy-LSD

• LA-MeO

• 5-MeO-DMT

• 12-Methoxy-LSD - Isomer Design

• 5-MeO-LSD (November 2019) - r/researchchemicals - Reddit

• 5-MeO-LSD ? (November 2015) - r/DrugNerds - Reddit