2,4-Dimethoxyamphetamine (2,4-DMA), also known as DMA-3, is a psychoactive drug of the phenethylamine and amphetamine families. It is one of the dimethoxyamphetamine (DMA) series of positional isomers.
In his book PiHKAL (Phenethylamines I Have Known and Loved), Alexander Shulgin lists 2,4-DMA's dose as greater than 60mg orally and its duration as "short". At a dose of 60mg orally, the effects of 2,4-DMA were reported to include definite threshold effects or even a bit more, a lot of amphetamine-like effects, some euphoria, and a psychedelic-like "diffusion of association". The drug's effects started to wear off after 3hours. According to Shulgin, 2,4-DMA could be a full stimulant and/or a full psychedelic at sufficiently high doses, but higher doses were not tested.
2,4-DMA has been found to act as a low-potency full agonist of the serotonin 5-HT<sub>2A</sub> receptor, with an of 2,950nM and an of 117%. It fully substitutes for DOM in rodent drug discrimination tests. The drug is less potent in this regard than 2,4,5-trimethoxyamphetamine (2,4,5-TMA or TMA-2), but is more potent than 3,4,5-trimethoxyamphetamine (3,4,5-TMA or TMA-1). 2,4-DMA fails to produce stimulus generalization to dextroamphetamine in rodent drug discrimination tests, suggesting that it lacks psychostimulant- or amphetamine-like effects.
The chemical synthesis of 2,4-DMA has been described.
2,4-DMA was first described in the scientific literature by Alexander Shulgin and colleagues by at least 1967. Subsequently, it was described in greater detail by Shulgin in PiHKAL in 1991.