N-Desethylisotonitazene (norisotonitazene) is a benzimidazole opioid with potent analgesic effects which has been sold as a designer drug.

It was first identified in 2023 as an active metabolite of the closely related compound isotonitazene, and was found to have similar potency.

It is one of the strongest benzimidazole opioids discovered, with an analgesic strength 20 times stronger than fentanyl.

Starting in 2023, it has become an increasingly widespread drug of abuse in its own right, linked to numerous overdose cases, and may be considered an analog of the schedule 1 drug metonitazene.

In October 2023, the DEA published an intent to temporarily schedule etonitazepipne and N-desethylisotonitazene.