MFEM, also known as 4-(2-fluoroethoxy)-2,5-dimethoxyamphetamine, is a serotonin receptor modulator of the phenethylamine, amphetamine, and DOx families. It is a derivative of the DOx psychedelics TMA-2 and MEM in which the 4-position substituent has been extended. The properties and effects of MFEM in humans appear to be unknown. The drug is a partial agonist of the serotonin 5-HT2A and 5-HT2B receptors and also shows other receptor interactions. MFEM was first described in the scientific literature by Daniel Trachsel by 2012.