Written by guitarist Joe Perry
and lead singer Steven Tyler, this song is about the band's struggles with addition (or, as Perry puts it, their "adventures in body chemistry"). A "monkey on one's back" is a term that means a burden, which is how they came to view their drug use. When the band finally sobered up for their 1987 album Permanent Vacation
, they enjoyed a career resurgence, got in great physical shape, and became video stars thanks to MTV.