"Rehab" is the eighth and final single taken from Rihanna's third studio album, Good Girl Gone Bad (2007) in the US and the UK. It was written by Justin Timberlake, Timbaland and Hannon Lane, with Timberlake and Timbaland contributing backing vocals in its bridge. As of November 25, the song has officially entered the Top 20 on pop radio. On November 23 2008, she performed this song at the 2008 American Music Awards.
"Rehab" was released to radio on October 7, 2008. "Rehab" had already been slated for release in August, 2008 in the UK but was pushed back due to the digital release of "Disturbia". Even without the official release yet, the song has been starting to pick up on pop radio as of the end of September. It has been played on New York City's Z100 late September. It was the fifth most added song to radio in Australia, on its first week of release.