Songfacts®:

• "Not OK" is the sound of 5 Seconds of Summer slipping into their bad influence era. It's a high-energy song about leaning into your "shadow side," the part of you that makes questionable decisions.
• The chorus, belted out by the whole band, goes full Eden with the line "Bite the apple, baby," a nod to the story of Adam and Eve. It symbolizes the embrace of temptation, sin, and the loss of innocence.
• Drummer Ashton Irwin contributes a late-night, regretful spoken section that appears near the end of the track. He explained to Rolling Stone it describes "a situation where I'd said some stupid s--t I didn't actually mean to somebody."
  
  But Irwin also sees the song as an ode to the band's bond with their fans and with each other: "We can kill our depression together, and we can experience these elevated feelings together," he said.
• Ashton Irwin, bassist Calum Hood and vocalist Luke Hemmings wrote the song with British songwriter/producer James "JHart" Abrahart, American singer-songwriter Sarah Hudson, and the track's producers, Jason Evigan and Mark Schick. Jhart, Hudson and Evigan previously collaborated with 5SOS on their 2022 track "Bad Omens."
• For "Not OK," 5SOS combined their usual pop-rock foundation with experimental electronic elements, fuzzy guitar riffs and hypnotic beats. According to Luke Hemmings, "It has the older 5 Seconds of Summer energy, but it's different, which is the whole M.O. of this chapter."
• "Not OK" was released as the lead single from 5 Seconds of Summer's sixth album, Everyone's a Star!. It became the band's fourth UK #1 album, following Sounds Good Feels Good in 2015, Calm in 2020 and 5SOS5 in 2022.