Bugonia director Yorgos Lanthimos tried to convince Emma Stone to keep her buzz cut.
The 36-year-old actress had to shave off her signature red locks for the comedy-sci-fi movie because the two kidnapping conspiracy theorists - Teddy (Jesse Plemons) and his cousin Don (Aidan Delbis) - believe the hair of her character, pharmaceutical firm CEO Michelle Fuller, is a communication device she can use to contact her mothership after they kidnap her after thinking she is an extraterrestrial being.
Lanthimos, 52, told Entertainment Weekly that he thought Stone looked so "amazing" with her new hairdo, but she said no to keeping it.
He added: "She had enough of [dealing with] months of having to also hide her head while we were filming."
In a scene, the kidnappers cut off Michelle's locks in the back seat of a stolen Range Rover, and it was done without any computer-generated imagery (CGI) - with Stone's actual hair falling onto the leather seats.
And Lanthimos credits the actress for agreeing to shave off her hair from the beginning.
Asked if it was tricky to convince Stone to shave off her locks, he said: "Not difficult at all, really. I mean, it was in the script, so I didn't even have to tell her.
"She read it first, and she had the slightest hesitation just before, not hesitation to do it, but she had kind of a knot in her stomach. But it happened. Thankfully, we did it.
"We only had one shot to achieve it. And then she felt great. She saw herself and she really loved it, and she felt very free."
Stone's co-star, Aidan, was in charge of shaving off Stone's hair.
And because the scene was filmed in one take, the actress feared messing it up if she opened her eyes or flinched while her hair was removed.
Asked what she was thinking when he removed her hair, Stone said: "Stay still. That was it. I was meditating on stay still, just stay still.
"Because I am not awake there, I was like, play dead, basically, play dead.
"It was one take and there were four cameras set up just to make sure."
As well as having a shaved head, Stone had to deal with Teddy and Don's mission to dull her alien powers by applying lots of lotion over her body.
Stone remembered: "It was a combination of [creams] and there were many tests of all different ones because it goes through all different layers.
"And turns out human skin hovers around 98.6 degrees, and that's a melting point for a lot of creams. So making that stuff last all day - tricky.
"The pores take it in, it thins out. So it was a combination of things, depending on the day, different foundations, moisturisers. It was a fun test, though."
