"Ecstasy" and "Molly" are common drug slang terms used among club and rave cultures to denote preparations believed to contain 3,4-methylenedioxymethamphetamine (MDMA). However, users of Ecstasy and Molly have increasingly tested positive for novel psychoactive substances (NPS), notably novel stimulants. To evaluate hypothesized non-specific and interchangeable use of the terms Ecstasy, Molly and MDMA, self-reported drug use was compared against toxicological findings in biological specimens. Oral fluid specimens were collected from participants attending large multi-day electronic dance music festivals in Miami, FL; Tampa, FL; and Atlanta, GA. Participants additionally completed a structured survey about recent recreational drug use. Collected specimens were screened for therapeutic drugs, common drugs of abuse and NPS using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF). Positive screen results were confirmed by validated liquid chromatography-tandem mass spectrometry (LC-MS-MS) methods for MDMA, MDA, methylone, dimethylone, ethylone, butylone, dibutylone, eutylone, pentylone, N-ethyl pentylone (ephylone), alpha-PVP and 4-fluoroamphetamine (4-FA). During this 4-year study, 223 participants provided an oral fluid specimen and indicated recent use of Ecstasy, Molly and/or MDMA/MDA. Of these subjects, 203 (91.0%) indicated only one of these drug terms; while 20 (9.0%) participants indicated a combination of multiple terms. Of the 203 participants designating only one drug term, 123 (60.6%) reported Molly use, 55 (27.1%) reported MDMA use and 25 (12.3%) reported Ecstasy use. Seven participants reported the use of MDA, but these responses were paired with MDMA responses due to detection of MDA as a metabolite of MDMA. The results from this study indicate that there are inconsistencies between admission to drug use and toxicological findings in this population. Of the 223 participants who indicated use of Ecstasy, Molly and/or MDMA/MDA, MDMA without a novel stimulant was confirmed in 121 (54.3%) participants, while 66 (29.6%) tested positive for at least one novel stimulant.