Fentanyl is an opioid drug help to treat pain conditions. It is used to manage extensive pain treatment. Fentanyl is a more effective drug, stronger than morphine up to 100 times and 50 times stronger than heroin. First, entire fentanyl in the where affect the reward system by releasing dopamine, a neurotransmitter that controls feelings and emotions. Fentanyl is available in different forms and strengths, including:-