MN 18 is an indazole-based synthetic cannabinoid that is an agonist for the cannabinoid receptors, with K<sub>i</sub> values of 45.72 nM at CB<sub>1</sub> and 11.098 nM at CB<sub>2</sub> and EC<sub>50</sub> values of 2.028 nM at CB<sub>1</sub> and 1.233 nM at CB<sub>2</sub>, and has been sold online as a designer drug. It is the indazole core analogue of NNE1. 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 MN-18 may release 1-naphthylamine, a known carcinogen. MN-18 metabolism has been described in literature.
MN-18 is banned in Sweden. On 15 September 2014 the Turkey government banned the sale of MN-18.