2F-Viminol is a pyrrole derived opioid analgesic drug, which was originally developed by a team at the drug company Zambon in the 1960s. It is around twice as potent as the parent compound viminol, though unlike viminol, 2F-viminol has never passed clinical trials or been approved for medical use. 2F-Viminol has been sold as a designer drug, first being identified in Sweden in 2019. It is one of a number of structurally atypical opioid agonists to have appeared on the designer drug grey-market since broad controls over fentanyl analogues were introduced in China in 2015. It was made illegal in Sweden in August 2019 and in Latvia in November 2019.