Songfacts®:

• The lead single from Three Days Grace's fifth studio album, this was the first song released by the band with new singer Matt Walst following the departure of Adam Gontier. The tune was released to US Rock radio on April 8, 2014.
• Drummer Neil Sanderson explained the song's meaning: "That song is about how everybody is addicted to something," he said. "It's written from the perspective of the vice that you need to be addicted to it. The love of the drug, it's the villain who taunts you into wanting more."
• Bassist Brad Waist told Artist Direct how the song came together. "It's one of the first songs we wrote with Matt," he explained. "He actually had an idea. He had a chorus line. I think he had 'Painkiller' and part of the riff. We said, 'Oh, that's wicked! We can work with that.'"
  
  "'Painkiller' is one of those songs that clicked right away," Waist added. "We were like, 'This is fantastic. Let's keep going.' We kept writing from there, and it's been great."
• This was Three Days Grace's 12th single to reach #1 on Mainstream Rock chart.