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.