HPLC-MS/MS stereoselective determination and quantification of MDMA and its phase-1 metabolite in human oral fluid samples: estimation of consumption time.
Journal of analytical toxicology March 15, 2026 Aurora Balloni, Sarah M R Wille, Giorgia Sprega et al.
MDMA (Ecstasy) is broken down and cleared from the body at different rates for its two mirror-image forms. In oral fluid from 161 samples, the S-(+)-enantiomer of MDMA was eliminated faster (half-life 3.3 hours) than the R-(-)-enantiomer (half-life 4.8 hours). Both reached peak levels within 1.75 hours after taking the drug. For the metabolite MDA, the second enantiomer cleared more quickly (half-life 9.6 hours) than the first (23.8 hours). The ratio of R to S MDMA increased over time, which could help estimate when the drug was taken. In roadside checks, 54.5% of cases had an R/S ratio above 1.5, suggesting use within the prior 24 hours.