Carpenter wrote it with songwriters Julia Michaels and Amy Allen and its producers, John Ryan, and Ian Kirkpatrick.

[1][2] She announced that she was working on her sixth studio album in March 2024, exploring new genres and expecting that it would herald a new chapter in her life.

Nathan Dantzler mastered the song with assistance from Harrison Tate, and Serban Ghenea mixed it at MixStar Studios in Virginia Beach with engineering from Bryce Bordone.

[15] Carpenter wrote the song "Bed Chem" with songwriters Julia Michaels and Amy Allen and its producers, John Ryan and Ian Kirkpatrick.

[25] Paste's Grace Robins-Somerville summarized "Bed Chem" as containing "Future Nostalgia-era Dua Lipa disco pastiche, the riffs-over-diction sigh-singing popularized by Ariana Grande, [and] a Swiftian pre-chorus".

[26] Billboard's Jason Lipshutz described the song as "a dreamy flirtation full of pinpoint vocals, personal touches, sexual innuendos and melodies".

[28] The title of the song, "Bed Chem", is shorthand for "bedroom chemistry",[29] and its lyrics revolve around Carpenter feeling an intense attraction to a man, leading her to imagine satisfying sexual encounters with him.

[31] During the bridge, Carpenter fantasizes that the encounter would probably turn out to be even better than her imagination, describing that they would "arrive at the same time" and set the temperature of the thermostat to 69.

[30] "Bed Chem" contains descriptions of the first time Carpenter met the subject, with lyrics stating that she was in a "sheer dress" and he donned a white jacket.

[36] While Robins-Somerville praised Carpenter's vocal performance, he was negative about the song's resemblance to the work of other artists and believed the pre-chorus could have been copied from multiple Taylor Swift albums.

[30] Rolling Stone's Rob Sheffield praised the rhyme about camaraderie as "Shakespearean", while The Daily Telegraph's Neil McCormick considered the pun "too rude to print".

[31] Nylon included "Bed Chem" in their list of the seven best songs of its release week, with Sofia Ante stating that Carpenter was "at her most charming — cheeky, seductive, and impossible to resist — that'll leave you blushing for three full minutes".

[57] The performance begins with the words "parental discretion is advised" being displayed on a screen,[58] and Carpenter sings the song on an onstage bed.

[59] Towards the climax, a man from her entourage enters with a camcorder and they undress behind shutting curtains as the lights gradually fade to darkness.

[60] At the tour's stop in Charlottesville's John Paul Jones Arena, cameras captured Keoghan giving a dizzy expression and hiding his face with his pass during the "Bed Chem" performance, drawing media attention.