4-Fluorobutyrfentanyl

4-Fluorobutyrylfentanyl (also known as 4-FBF and p-FBF) is an opioid analgesic that is an analog of butyrfentanyl and has been sold online as a designer drug. It is closely related to 4-fluorofentanyl, which has an EC50 value of 4.2 nM for the human μ-opioid receptor.

4-Fluorobutyrfentanyl

4-Fluorobutyrylfentanyl (also known as 4-FBF and p-FBF) is an opioid analgesic that is an analog of butyrfentanyl and has been sold online as a designer drug. It is closely related to 4-fluorofentanyl, which has an EC50 value of 4.2 nM for the human μ-opioid receptor.