"Chemicals React" is a song written and recorded by American pop rock duo Aly & AJ, for the deluxe edition reissue of their debut album Into the Rush (2005).

The Michalka sisters co-wrote the song with Antonina Armato and Tim James of production duo Rock Mafia, who also produced the track.

Hollywood Records serviced the song to contemporary hit radio in the United States on June 27, 2006.

"Chemicals React" failed to chart on its first release in June 2006, but after its re-release in September 2006, the song entered the Billboard Hot 100 at number 70.

[9] The music video was directed by Chris Applebaum and features Aly & AJ lip synching the song live.