Fentanyl was first made by Paul Janssen in 1960 and approved for medical use in the United States in 1968.[3][8] In 2015, 1,600 kilograms (3,500 pounds) were used in healthcare globally.[9] As of 2017, fentanyl was the most widely used synthetic opioid in medicine;[10] in 2019, it was the 278th most commonly prescribed medication in the United States, with more than 1 million prescriptions.[11][12] It is on the World Health Organization's List of Essential Medicines.[13]