The song was released on April 1, 2014, as the lead single from their fifth studio album Human.

[1] It is the first single released with new singer Matt Walst, following the departure of Adam Gontier.

[3] Within the announcement, it was teased that new music would be heard the following week and on March 31, the band premiered "Painkiller" on their YouTube channel.

"[5]"Painkiller" was written by Johnny Andrews, Douglas Ryan Oliver, Neil Sanderson, Barry Stock, Brad Walst and Matt Walst while production was handled by Gavin Brown who also co-wrote the track.

[6] The song was recorded in Noble Street Studios, Toronto, Ontario, in late 2013.