Mdma has become widely known as ecstasy (shortened e, x, or xtc), usually referring to its tablet form, although this term may also include the presence of possible adulterants or diluents. Mdma (3-4 methylenedioxymethamphetamine) is a synthetic, psychoactive drug with a chemical structure similar to the stimulant methamphetamine and the hallucinogen mescaline. It commonly.