JWH-164 is a synthetic cannabinoid receptor agonist from the naphthoylindole family. It has approximately equal affinity for the CB1 and CB2 receptors, with a Ki of 6.6nM at CB1 and 6.9nM at CB2. JWH-164 is a positional isomer of the related compound JWH-081, but with a methoxy group at the 7-position of the naphthyl ring, rather than the 4-position as in JWH-081. Its potency is intermediate between that of JWH-081 and its ring unsubstituted derivative JWH-018, demonstrating that substitution of the naphthyl 7-position can also result in increased cannabinoid receptor binding affinity.[1][2]