High Quality Content by WIKIPEDIA articles! 4-Methylthioamphetamine (4-MTA) is an illicit drug and research chemical developed in the 1990s by a team led by David E. Nichols at Purdue University. It acts as a non-neurotoxic highly selective serotonin releasing agent (SSRA) in animals. It is distantly related to several other SSRAs, including MMAI, MDAI, and MDMAI.