ecstasy, either of two drugs used for their euphoric effects. The original ecstasy, a so-called designer drug, also known as MDMA, is an analog of methamphetamine (see amphetamine). The other drug is a substance also known as ma huang or ephedra; it was marketed as "herbal ecstasy" to promote the idea that it is a natural and safe form of ecstasy. The active ingredient of herbal ecstasy is ephedrine.