4-Me-ñMT (developmental code name MP-809), or 4-Me-AMT, also known as 4-methyl-ñ-methyltryptamine or as 4,ñ-dimethyltryptamine (4,ñ-DMT), is an experimental antidepressant of the tryptamine and ñ-alkyltryptamine families that was never marketed. It is closely structurally related to serotonergic psychedelics and entactogens like ñ-methyltryptamine (ñMT) and ñ-ethyltryptamine (ñET).
4-Me-ñMT is active at a dose of 20 to 60mg orally in humans, though described as being an antidepressant rather than a hallucinogen. It was found to be effective as an antidepressant in preliminary clinical studies. Alexander Shulgin has said that 4-Me-ñMT produced some feelings of unreality at 20mg, as well as skin flushing, muscle tightness, and mydriasis. However, he has said that it could not be called a hallucinogen at assessed doses and has listed the hallucinogenic dose as being greater than 60mg.
4-Me-ñMT partially reverses reserpine-induced behavioral depression in rodents (by up to 60%), but does not produce hyperlocomotion. This was the case at a dose of 50mg/kg, whereas ñMT produced clear hyperlocomotion and near-fully reversed reserpine-induced hypoactivity (by 95%) at a dose of 15mg/kg. Hence, 4-Me-ñMT shows reduced antidepressant- and psychostimulant-like potency compared to ñMT. It is also less active than ñET. The drug is said to have very weak monoamine oxidase inhibition.
Analogues of 4-methyl-AMT include ñ-methyltryptamine (AMT), 4-methyl-AET, 4-methyl-DMT, 4-HO-AMT, 4-HO-AET, and RS134-49 (4-methyl-THPI), among others.
4-Me-ñMT was first described in the scientific literature by 1962. It was investigated as an antidepressant by Sandoz in Canada in the early 1960s, although it was never marketed.