mdmb-4en-pinaca mdmb-4en-pinaca mdmb-4en-pinaca (also incorrectly known as 5-cl-adb-a) is an indazole-based synthetic cannabinoid that has been sold online as a designer drug. in 2021, mdmb-4en-pinaca was the most common synthetic cannabinoid identified by the drug enforcement administration in the united states. mdmb-4en-pinaca differs from 5f-mdmb-pinaca due to replacement of 5-fluoropentyl with a pent-4-ene moiety (4-en). mdmb-4en-pinacalegal statuslegal status ca: schedule ii de: anlage ii (authorized trade only, not prescriptible) uk: class b identifiers iupac name methyl (s)-3,3-dimethyl-2-(1-(pent-4-en-1-yl)-1h-indazole-3-carboxamido)butanoate cas number2504100-70-1 ypubchem cid155804661chemspider71117180uniik2dzn2tdd6chemical and physical dataformulac20h27n3o3molar mass357.454 g·mol−13d model (jsmol)interactive image smiles o=c(n(c(c)(c)c)c(oc)=o)c1=nn(cccc=c)c2=c1c=cc=c2 inchi inchi=1s/c20h27n3o3/c1-6-7-10-13-23-15-12-9-8-11-14(15)16(22-23)18(24)21-17(19(25)26-5)20(2,3)4/h6,8-9,11-12,17h,1,7,10,13h2,2-5h3,(h,21,24)/t17-/m1/s1key:lwocbhbfwngpgm-qgzvfwflsa-n it acts as a potent agonist of the cb1 receptor with an ec50 value of 2.47 nm. legal status sweden's public health agency suggested classifying mdmb-4en-pinaca as a hazardous substance, on december 18, 2019. in the united states, the dea has filed a notice for its intent to temporarily place mdmb-4en-pinaca into schedule i status starting on or after may 4th, 2023 for up to 2 years, during which it's possible the dea could file for permanent scheduling within those 2 years. if it's filed on may 4, 2023, and the dea does not file to permanent placement the temporary schedule i order will expire on may 4, 2025.