3,4-Ethylenedioxy- N -methylamphetamine ( EDMA ) is an entactogen drug of the amphetamine class.   It is an analogue of MDMA where the methylenedioxy ring has been replaced by an ethylenedioxy ring.   EDMA was first synthesised by Alexander Shulgin.  In his book PiHKAL , the dosage is listed as 150–250 mg, and the duration listed as 3–5 hours.  According to Shulgin, EDMA produces a bare threshold consisting of paresthesia, nystagmus, and hypnogogic imagery, with few to no additional effects.  Scientific research has demonstrated that EDMA acts as a non- neurotoxic serotonin releasing agent with moderately diminished potency relative to MDMA, and with negligible effects on dopamine release.  Based on Shulgin's reports of essential inactivity at 150–250 mg, it might be more active at higher doses.