"Do Somethin'" was originally written and produced for European girl group Melodi Brown in late 2002. Their album and their version of the song were never released and the song was given to Britney.
It was featured on her first greatest hits compilation, Greatest Hits: My Prerogative (2004). It was written and produced by Bloodshy & Avant, with additional writing by Henrik Jonback and Angela Hunte. Originally, the song was never intended to be released as a single. .