2,3,4-Trimethoxyamphetamine (2,3,4-TMA), also known as TMA-3 or as ñ-methylisomescaline, is a putative psychedelic drug of the phenethylamine and amphetamine families. It is one of the possible positional isomers of trimethoxyamphetamine and is a positional isomer of 3,4,5-trimethoxyamphetamine (TMA or TMA-1).
In his book PiHKAL (Phenethylamines I Have Known and Loved) and other publications, Alexander Shulgin lists 2,3,4-TMA's dose as greater than 100mg orally and its duration as unknown. The drug produced no effects whatsoever at a dose of 100mg in three separate individuals. Higher doses were not tested, but 2,3,4-TMA could possibly be active at higher doses.
2,3,4-TMA shows affinity for serotonin receptors. It substituted for DOM in rodent drug discrimination tests.
The chemical synthesis of 2,3,4-TMA has been described.
2,3,4-TMA was first described in the scientific literature by Alexander Shulgin in 1964. Subsequently, it was described in greater detail by Shulgin in his 1991 book PiHKAL (Phenethylamines I Have Known and Loved).
2,3,4-TMA is a controlled substance in Canada under phenethylamine blanket-ban language.
As a positional isomer of 3,4,5-trimethoxyamphetamine (TMA), 2,3,4-TMA is a Schedule I controlled substance in the United States.