Endo International plc is an American Irish-domiciled generics and specialty branded pharmaceutical company that generated over 93% of its 2017 sales from the U.S. healthcare system.

[8][6] Endo Pharmaceuticals Holdings was created as a result of a $277 million management buyout of the division from DuPont Merck in 1997, led by Carol Ammon.

[45] It was the first time that the FDA had "taken steps to remove a currently marketed opioid pain medication from sale due to the public health consequences of abuse.

[51] Endo Pharmaceuticals at various times was a significant funder of the American Pain Foundation, which has been accused of producing misleading and biased materials relating to opiod prescribing.

[52][53] APF shut down in 2012 after the United States Senate Committee on Finance began an investigation into the relationships between narcotic manufacturers and pain advocacy organisations.