If you thought Christopher Nolan's Oppenheimer was nuts, just wait until you hear what went into making it.
After all, Cillian Murphy was looking to be explosive while transforming into J. Robert Oppenheimer, a.k.a. the father of the atomic bomb.
"Oppenheimer had a very distinct physicality and silhouette, which I wanted to get right," the 47-year-old told the New York Times of the scientist, who died from cancer in 1967. "I had to lose quite a bit of weight, and we worked with the costume and tailoring; he was very slim, almost emaciated, existed on martinis and cigarettes."
The Irish actor's diet was a bit different, but just as jarring, according to his costar Emily Blunt, who plays Oppenheimer's wife Kitty.
"He had such a monumental undertaking," she told Extra. "And he could only eat, like, an almond every day."
And, reader, he doesn't recommend you try this at home.
"You become competitive with yourself a little bit which is not healthy," he told The Guardian, refusing to share just how many pounds he dropped. "I don't want it to be, ‘Cillian lost x weight for the part.'"
And if you have, you know, gone to the movie theaters (or streamed anything at home), you know he's hardly the first shape up for a role—and he won't be the last.
Keep reading to see stars like Tom Hanks and Anne Hathaway who have undergone drastic transformations on screen...
Plus, Oppenheimer (also starring Matt Damon and Robert Downey Jr.) is out now.