"Interesting Drug" was the fourth solo single released by Morrissey. The song was not featured on one of Morrissey's main studio albums, but can be found on the compilation album Bona Drag along with the B-side "Such a Little Thing Makes Such a Big Difference". It features Kirsty MacColl on backing vocals as well as his former colleagues in The Smiths, Andy Rourke, Mike Joyce and Craig Gannon. All three also appear on the B-sides.