2,4-Dimethoxyamphetamine

2,4-Dimethoxyamphetamine (2,4-DMA), also known as DMA-3, is a drug of the phenethylamine and amphetamine families. It is one of the dimethoxyamphetamine (DMA) series of positional isomers.

It was reported by Alexander Shulgin to be active at a dose of 60 mg orally and to produce threshold amphetamine-like stimulant and euphoric effects. However, there was also a "diffusion of association" and Shulgin stated that it was more than just a stimulant. The duration was described as short and effects subsiding at 3 hours. Per Shulgin, the drug could be a full stimulant and/or a full psychedelic at sufficiently high doses, but higher doses were not pursued.

2,4-DMA has been found to act as a low-potency full agonist of the serotonin 5-HT_2A receptor, with an EC₅₀Tooltip half-maximal effective concentration of 2,950 nM and an E_maxTooltip half-maximal effective concentration 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.