FDU-NNE1 (also known as FDU-NNEI and FDU-MN-24) is an indole-based synthetic cannabinoid that is presumed to be a potent agonist of the CB1 receptor and has been sold online as a designer drug.[1][2] Given the known metabolic liberation (and presence as an impurity) of amantadine in the related compound APINACA, it is suspected that metabolic hydrolysis of the amide group of FDU-NNE1 will release 1-naphthylamine, a known carcinogen.