Mewes wouldn't start using heroin until two films after Clerks. Following a roller coaster ride on the set of Mallrats, in which he went from being so distrusted by the studio that they kept Seth Green on standby to play his role, to becoming the studio darling after they saw his dailies, Mewes was offered a role that wasn't the "Jay" character he'd created. Mewes shot the film Drawing Flies in Vancouver, where he got his first taste of the drug he'd sworn he would never try.
At this point Mewes' mother was out of jail — and HIV positive, presumably from her history of sharing drug needles. Mewes, hoping to avoid her fate, rationalized that snorting heroin would be a safer choice than shooting the drug. He returned home with months to kill between film work, and a lack of cash that forced him to go back to jobs roofing and delivering pizzas. His depression and boredom led to even more drug use, including cocaine and crack.
Remembering that day in Vancouver when he first tried heroin, Mewes told The Fix, "If I could go back, I would definitely tell myself not to do drugs."