Songfacts®:

• Can't take it back once it's been set in motion
  You know I need you for the oxytocin
  
  Oxytocin is a feel-good hormone found in mammals, which plays a number of roles:
  
  1) The hormone is released into the bloodstream during labor, which helps with birth and bonding with the baby and milk production.
  
  2) Oxytocin is distributed when parents and children look into each other's eyes or embrace.
  
  3) It is also released during intimate moments such as cuddling or orgasms.
  
  For these reasons it is sometimes dubbed the "love hormone."
  
  Here, Billie Eilish sings of releasing the hormone during sexual activity.
• "Oxytocin" is a track on Happier Than Ever, which Eilish released at age 19. It is the most overtly sexual song she'd released to date; her previous material being more teenage-romance related.
• The sex Eilish sings of during this slinky track is clearly of the kinky variety.
  
  I wanna do bad things to you
  I wanna make you yell
  
  Eilish told Spotify she was "going through crazy feelings at the time."
• Billie Eilish's parents aren't especially religious, but the pop star had a strong Christian faith as a child. She has since changed her beliefs to an all-roads-lead-to-God philosophy. Here, she refers to God as a woman.
  
  If you only pray on Sunday, could you come my way on Monday?
  'Cause I like to do things God doesn't approve of if She saw us
  
  This is not the first time Eilish has portrayed God as a female. On the When We All Fall Asleep, Where Do We Go? track "All the Good Girls Go to Hell," she sang:
  
  All the good girls go to hell
  'Cause even God Herself has enemies
• Eilish co-wrote "Oxytocin" with her producer brother Finneas. The same sibling song-composition team wrote all the songs on Happier Than Ever as well as her debut album, When We All Fall Asleep, Where Do We Go?
  
  Speaking to Rolling Stone about penning such sexual tracks with her brother, Eilish admitted, "We kind of have to plug our ears when we're writing about desire for other people because we're f---ing siblings."
• Talking to Spotify about Finneas' techno production, Eilish said they had future concerts in mind when creating this track. "We had all these songs and I was like, 'The only thing we're missing is the song that's going to be purposefully insane live," she recalled. "And we made 'Oxytocin.' It was the most satisfying thing in the world. We would stand up and jump around and see what felt right."