Here are some of the most interesting behind the scenes facts and legendary moments that made American Psycho , a cult classic:

Christian Bale didn’t just play Patrick Bateman, he became him.
While most actors prepare for roles by reading the script and discussing character motivations, Bale took it to another level. He completely transformed his body, worked out religiously, and made sure his physique looked as polished and "perfect" as Bateman would demand.
One of the most legendary details?
Yep, this wasn’t just Bateman showing on screen, Bale literally did workouts in between scenes to make sure his muscles looked pumped. This was his idea, completely in line with Bateman’s obsession with physical perfection.
Mary Harron later joked in interviews that Bale was the most disciplined actor she had ever worked with. She said he was like a machine, never breaking character, always keeping Bateman’s cold, detached persona intact, even when the cameras weren’t rolling.

Adapting American Psycho from page to screen was a challenge. The novel was infamous for its extreme violence, and while the filmmakers wanted to keep the satire intact, they also knew that filming certain scenes as written would have made the film unreleasable.

Guinevere Turner, who co-wrote the screenplay with Mary Harron, also acted in the film. She played Elizabeth, one of Bateman’s victims in the infamous threesome scene.
In interviews, Turner admitted that they toned down the gore from the book because they knew the MPAA would never allow it. Even with the changes, the film still struggled with ratings issues, nearly getting slapped with an NC-17 rating before they made careful edits to a few scenes.

One of the hardest things about making American Psycho? Figuring out how to market it.