According to the Centers for Disease Control and Prevention, the pharmaceutical fentanyl is a synthetic opioid approved for treating severe pain, typically advanced cancer pain. Fentanyl is 50 to 100 times more potent than morphine and is prescribed as transdermal patches or lozenges. The CDC says the most recent cases of fentanyl-related harm, overdose, and death in the U.S. are linked to illegally made fentanyl.Learn more about your ad choices. Visit megaphone.fm/adchoices