5-Thiometaescaline (5-TME), also known as 3-ethoxy-4-methoxy-5-methylthiophenethylamine, is a psychoactive drug of the phenethylamine and scaline families related to mescaline. It is the analogue of metaescaline in which the methoxy group at the 5 position has been replaced with a methylthio group. The drug is one of three possible positional isomers of thiometaescaline (TME), the others being 3-thiometaescaline (3-TME) and 4-thiometaescaline (4-TME).
In his book PiHKAL (Phenethylamines I Have Known and Loved) and other publications, Alexander Shulgin lists 5-TME's dose as greater than 200mg orally and its duration as unknown. The effects of 5-TME have been reported to include possible tinnitus, a possible brush of lightheadedness, and nothing else, but these changes could not be clearly ascribed to the drug.
The chemical synthesis of 5-TME has been described.
5-TME was first described in the scientific literature by Alexander Shulgin and Peyton Jacob III in 1984. Subsequently, it was described in greater detail by Shulgin in PiHKAL in 1991.