Fentanyl is a synthetic opioid that is primarily used as a pain medication, particularly for severe and chronic pain. It is also used with other medicines immediately before or during surgery to help the anesthetic work better. It is a potent opioid analgesic, meaning it is a highly effective pain reliever. When used under the supervision of a healthcare professional and according to prescribed guidelines, the risk of addiction associated with fentanyl (as with other opioid pain relievers) can be minimized.