Norfentanyl

Norfentanyl is an inactive synthetic opioid analgesic drug precursor. It is an analog and metabolite of fentanyl with the removal of the phenethyl moiety (or functional group) from fentanyl chemical structure.

Occurrence and Applications
Norfentanyl occurs primarily as a metabolite of its parent drug, fentanyl. However, it can also be used to synthesize fentanyl itself.