5F-MN-24, also known as 5F-NNEI or 5F-MN-24, is an indole-based synthetic cannabinoid, that is presumed to be a potent agonist of the CB1 receptor. Because the metabolic liberation (and presence as an impurity) of amantadine in APINACA, it is suspected that metabolic hydrolysis of the amide group of 5F-NNE1 may well release 1-naphthylamine, which is a known carcinogen.