This is a list of fentanyl analogues. * 2,5-Dimethylfentanyl * 3-Allylfentanyl * 3-Methylbutyrfentanyl * 3-Methylfentanyl * 3-Methylthiofentanyl * 4-Fluorobutyrfentanyl * p-chloroisobutyrfentanyl * p-fluoroisobutyrfentanyl * 4-Fluorofentanyl * 4-Phenylfentanyl * 4-Methoxybutyrfentanyl * Acrylfentanyl * α-Methylacetylfentanyl * α-Methylbutyrfentanyl * α-Methylfentanyl * α-Methylthiofentanyl * Acetylfentanyl * Alfentanyl * Benzylfentanyl * β-Hydroxyfentanyl * β-Hydroxythiofentanyl * β-Methylfentanyl * Butyrfentanyl * Brifentanyl * Carfentanyl * Cyclopentylfentanyl * Isobutyrfentanyl * Furanylfentanyl * Furanylethylfentanyl