“Oxytocin” is a song by American singer-songwriter Billie Eilish from her second studio album, Happier Than Ever (2021). The song was written by Eilish, and produced and co-written by Finneas, who provides backing vocals. It was the last track created for the album, being intended by the singer to be insane live. A dance, EDM, electronica, electropop, industrial pop and techno track, the song has been described by music critics as horny, upbeat and her sexiest song yet.
Described as fan favorite, “Oxytocin” received widespread acclaim from music critics, some of whom compared it to works of Crystal Castles, Grimes, Nine Inch Nails, and Timbaland. Numerous critics saw similarities between the song and Eilish’s debut material, most notably “Bad Guy“. The song charted in a number of countries upon the release of Happier Than Ever, including reaching the top 40 in Australia, Denmark, Hungary, Ireland, Lithuania, Norway, and the United Kingdom, while appearing at number 72 in the United States. Eilish performed it during her concert film Happier Than Ever: A Love Letter To Los Angeles and on music festivals such as iHeartRadio Music Festival and Life Is Beautiful Music & Art Festival.
“The [color] of whatever was in my brain while making it was dark, but also a flashing yellow. Honestly, the images I have for ‘Oxytocin’ were just sex. That’s it. All different kinds, and styles, and [colors], and locations. That’s really what was in my head. Sex.”
—Eilish talking about the song to The Guardian.
“Oxytocin” was written by Billie Eilish and Finneas, while the latter produced the track and provided backing vocals. It was the last track created for Happier Than Ever, being recorded on February 16, 2021 in Finneas’ basement studio, replacing “What I Wanna Hear?” on the album’s final track listing. The singer spoke about the creative process behind the song, and said that it is named after the hormone of the same name, which is released due to love or childbirth. In an interview with The Guardian, Eilish talked about inspiration for the track, saying that “[t]here was flashing in [her] head”, adding that she had sex images in her mind during the recording. Addidtionally, she admitted that in the song’s background, barking of her dog Shark can be heard.
She also noted that the album had been “missing” a song that would expressly “be insane live”, which was why “Oxytocin” was created. She also mentioned that while performing the song, she thinks about sex. The singer also said that “Oxytocin” is the “most satisfying” song, and added that it is one of her favorite tracks from the album. Finneas was proud of how the song came out due to its “gated tremolo and distortion”.