This song describes what it’s like to spend a day on heroin from the point of view of the drug user. Lou Reed, having struggled with addiction himself (and having written other songs on the subject, i.e. “Heroin” from his The Velvet Underground days) portrays why people, including him, do heroin, despite its dire consequences (shown in the “reap just what you sow” lines at the end). It was included in the soundtrack for the film adaptation of Irvine Welsh’s Trainspotting, a film about heroin addicts expanding on the themes of the song.

While the primary interpretation of this song is that it operates as a metaphor for drug use, it is worth noting that Lou’s first love, Shelley Albin, may be the inspiration for it. A few years after they split, Albin had returned to New York with her new husband. She had an affair with Lou, who ultimately reverted back to his old ways (mind games, manipulation, etc.) and Albin left him for good. In this light, “You’re going to reap just what you sow” sounds as though Lou is chastising himself for his ways, which have once again cost him the woman that he felt most compatible with.