"Irresistible" is a groove-laden song, following a musical setting that is beat-oriented. In an interview with Associated Press, Simpson said that "Irresistible" is "very sexy, more grown-up. I think you're going to see a new side of Jessica Simpson." Lyrically, according to Birgisson, the song carries some feminine viewpoints that Sheyne had managed to incorporate through her contribution. Ben Graham, the author of Maximum Jessica Simpson, noted that the lyrics suggest that Simpson finds it hard to keep her famous virginity image intact. This can be inferred from the lines "I know that I'm supposed to make him wait / Let him think I like the chase / But I can't stop fanning the fire / I know I meant to say no… / But he’s irresistible," Bob Waliszewski of Plugged In pointed out that the verses "I can't stop fanning the fire [...] Now inescapable" refer to an "imminent sexual compromise". "She knows she shouldn't give in, but seems past the point of no return," he explained. However, Taylor stated that lyrically, the song demands for "total fulfillment". The version featured on Lizzie McGuire soundtrack replaces the lyric "When he makes me weak with desire" with "When he makes me want to move closer" and "But I can't stop fanning the fire / I know I meant to say no" with "But it's time to stop this emotion / Right now I'm gonna say no." Remixes and release "Irresistible" was commissioned for remixes from So So Def Recordings, Hex Hector, and Dezrok. The So So Def remix of the song, produced by Jermaine Dupri, features American rapper Lil' Bow Wow and Dupri himself. It samples the Kool & the Gang's song, "Jungle Boogie" (1973). Another remix of the song was produced by American producer Hex Hector. According to Slant Magazine, the Hex Hector remix of the song uses full-throated vocals by Simpson, and includes disco-influenced string arrangement, which is comparable to the musical style of Giorgio Moroder, and utilizes beats from a Roland TR-808. Ron Thal, the current lead guitarist of the hard rock band Guns N' Roses, plays guitar on the remix tracks. Both of the remixes are included on Simpson's remix extended play (EP) This Is the Remix (2002). Brendan Frederick of Complex wrote that while the remix could not do anything to complement the original track's chart performance, it helped achieve a "gimmicky redemption". He also