Agradecimentos: The authors thank the Superintendence of the Technical Scientifc Police of the State of Sao Paulo for kind donation of data, and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES—Projeto INSPEQT, Edital No. 16/2020), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, Processo 2021/09857-8) and Conselho Nacional de Desenvolvimento Científco e Tecnológico (CNPq) for the fnancial support Ver menos

Abstract: MDA-19 or BZO-HEXOXIZID (N'-[(3Z)-1-(1-hexyl)-2-oxo-1,2-dihydro-3H-indol-3-ylidene]-benzohydrazide), in a more recent nomenclature, was first synthesized in 2008 as a selective type-2 cannabinoid receptor (CB2) agonist due to its potential to treat neuropathic pain. In Brazil, this substance was identified in a series of 53 apprehensions between September 2021 and February 2022. Nevertheless, what intrigues toxicologists is that BZO-HEXOXIZID does not exert significant type-1 cannabinoid receptor (CB1) agonism—which is responsible for the well-known psychoactivity of ?-9-tetrahydrocannabinol. Thus, the objective of this work is to report the first apprehension and identification of BZO-HEXOXIZID in Brazil and to discuss pharmacologically the possible reasons why a CB2 agonist has been incorporated to the illicit market. Suspected seized samples were sent to the Laboratory of the Scientific Police of the State of Sao Paulo. After the screening, samples were confirmed for the presence of BZO-HEXOXIZID using chromatography gas—mass spectrometry, Fourier-transform infrared spectroscopy and nuclear magnetic resonance techniques. Of the 53 samples analyzed, 25 contained only BZO-HEXOXIZID and 28 with mixtures, of which 11 with the CB1 agonist ADB-BUTINACA. Other substances were found in association such as cocaine and caffeine. BZO-HEXOXIZID was detected in a series of seized materials for the first time in Brazil. Nevertheless, there are still unanswered questions regarding the use of this selective CB2 agonist as a drug of abuse Ver menos