“Mr. Brownstone” was only released as a promotional single in the UK ahead of the release of Appetite for Destruction in 1987. It was featured as the B-Side of both “Welcome to the Jungle” and “It’s So Easy.” As a staple of live Guns N' Roses shows, the song was the first to be written after signing to Geffen Records.
In his autobiography, Slash explained that the lyrics depict a typical day in the life of Guns N' Roses. Both the lyrics and music were improvised by Slash and Izzy Stradlin while complaining about being addicts—“brownstone” is a slang term for heroin. Throughout the song, explicit references are made about building a tolerance to the drug.