Naphthoylindoles are a class of synthetic cannabinoids.[1]
Behaving similarly in vivo to endocannabinoids such as anandamide or 2-arachidonoylglycerol (2-AG), Naphthoylindoles can bind to endocannabinoid receptors in animals, presenting as CB1 and/or CB2 partial/full agonists.
They have gained notoriety over the years for illicit usage and distribution in Europe and North America, typically marketed as "herbal incense blends."[2]