About Side Effects (feat. Emily Warren)

"Side Effects" is a song by American music production duo the Chainsmokers, featuring guest vocals from American singer Emily Warren. Written by Andrew Taggart, Warren, Tony Ann, Corey Sanders and Sly, with production handled by the Chainsmokers and Sly, it was released by Disruptor Records and Columbia Records on July 27, 2018, as the fifth single from the Chainsmokers' second studio album, Sick Boy.

The duo first teased new music on July 6, 2018, writing in a tweet: "Getting close to that time for some new music." They revealed parts of the official cover art on July 19 and 20, and officially announced the song on July 23. On July 25, KIIS-FM's Tanya Rad interviewed the duo about the single while backstage at the Hollywood Palladium, they shared who they played the song for first and the reason behind choosing this song as their next single. A day prior to the single's release, they posted a short audio teaser. "We felt it was time for a summer jam rooted in the sound we created when we first started making records," the Chainsmokers said in a press release. "Our music is always a current reflection of how we feel, what inspires, and who we are in that particular moment." In an interview with Billboard, the duo was asked about the disco-type vibe of "Side Effects", which differs from their other releases in 2018. Andrew Taggart of the Chainsmokers said: "It's definitely funky. We felt like our music has been like in a much slower, more mellow place. And it's summertime, and we feel like we really wanted to make an upbeat summertime record—and that's what we came up with. We also made 'Sick Boy' and 'You Owe Me' during the winter, and it was a darker time and we were dealing with a bunch of personal stuff." Talking about the inspirations behind the lyrics, he said that despite their love for "writing about millennial relationships", they also "write about what [they] observe, and [they] write about making bad decisions often, but also kind of being impulsive in getting into them, and also living in the moment, as [they] find beauty in those small moments," which was demonstrated in this song. The song features Emily Warren, whom Alex Pall called "one of [their] favorite human beings", is the duo's longtime collaborator. "When you're comfortable with someone and they know you well, it's really easy to make music that you enjoy and are excited about. It's really exciting that she's featured on this record and hopefully the world loves it, 'cause I think it's time that they all get to know who Emily Warren is," Pall explained.