Ethylbromazolam is a novel psychoactive substance (NPS) structurally similar to the known benzodiazepine bromazolam. This ethyl analog emerged on the illicit drug market in early 2025, with reports of detection in multiple countries throughout that year and more following in 2026. Much is known about bromazolam, but limited information is available on the pharmacology and toxicology of this new ethyl analogue. This study uses pooled human liver microsomes and LC-MS/MS analysis to identify presumptive phase I metabolites of ethylbromazolam, supporting forensic toxicologists in detecting emerging designer benzodiazepines.

To cite this monograph: Bassman, J.R., Layle, N.K., Goodwin, S.K., et al. Ethylbromazolam. Cayman NPS Metabolism Monograph Issue 5 (2026).