A mid-forties woman purchased seven different dietary supplements from Thailand on the internet and subsequently died after taking these supplements. Since there were no ingredient labels on the supplements, we identified the active ingredients using direct analysis in real time–mass spectrometry (DART®–MS), direct exposure probe–MS (DEP–MS), and liquid chromatography–MS (LC–MS). DART®–MS gives exact molecular weights and DEP–MS shows the fragmentation of a molecule by electron ionization. Analyses using these two instruments are rapid and do not require extraction of the sample. The compounds predicted by DART®–MS and DEP–MS were confirmed by LC–MS and the active ingredients of the seven dietary supplements were identified.