 "Poison" is an up-tempo electropop and dance-pop song produced by RedOne, BeatGeek and Jimmy Joker. It was written by Scherzinger, Bilal Hajji, Kinda Hamid, Novel Jannusi, Achraf Jannusi, RedOne in the musical key of A-minor. With a guitar-driven melody, "Poison" uses a pulsating and toxic beat throughout, which is similar to that used in the Britney Spears song, "Toxic". The lyrics were also compared to "Toxic" and said to have similar themes, according to BBC Music blogger, Fraser McAlpine. A reviewer from Rap-Up spoke of the song's overall theme. "The lead Pussycat Doll has thoughts of using a deadly elixir on the dance floor, singing through a fuzzy filter over bombastic synthesizers." They described the song as a "toxic pop gem". According to the sheet music published at Musicnotes.com by Sony / ATV Music Publishing, the song has a time signature set in common time, with a tempo of 124 beats per minute. The melody is mainly composed with piano and guitar instruments.
