If You Thought Demi Moore’s Transformation Was Crazy in ‘The Substance,’ Wait Til You Hear How They Did It

Boobs sprouting, spines separating, heads exploding — in Coralie Fargeat’s The Substance, nothing is off-limits. That’s what quickly became clear to prosthetics designer Pierre-Olivier Persin when he began working on the Mubi movie in which Demi Moore takes a fountain-of-youth drug with some jaw-dropping (literally) side effects.

“They always say to you, ‘I have this script with lots of prosthetic work in it,’ but then you end up with two aging makeups, and that’s it,” the veteran Persin (Game of Thrones) tells THR, saying that this is the most prosthetics work he’s ever done on a project. “With The Substance, when I read the script, it fell out of my hands, and I went, ‘Wow, I need to meet with Coralie.’ ”

The body-horror thriller, which leans mostly on practical effects, follows Moore’s character, Elisabeth Sparkle, a fading celebrity, as she takes a black-market drug that creates a temporary younger version of herself named Sue and then must grapple with the fallout.

Persin and his team used two stunt doubles and two body doubles for Moore, applying prosthetics to the actress and the four other women. “Demi was willing to do as much as possible,” says Persin. For a “birth” scene, where the “other self” is born through the open spine, Persin used puppetry as well as prosthetic appliances on the body double to ensure it looked as real as possible (see opposite page).

Margaret Qualley, who plays Moore’s younger self, sported fake breasts in the movie that Persin made by taking a live cast of Qualley, then producing silicon gel appliances that he then stuck on the actress before coloring and blending. He explains: “It’s pretty much the same process for every prosthetic: You start with the live cast or scan, then you sculpt the change you want to obtain, and then you mold those sculptures. Then you use silicon or whatever material you are working with, then you stick them on and paint them.”

Persin’s first project documenting Elisabeth’s decay involved a finger, also the first body part that experiences the side effects of the drug in the film. “I remember Coralie wanted to go a little bit too far too quickly for the first stages,” notes Persin. “I thought, ‘Eventually she’s going to turn into that grotesque hag, so maybe step by step would be better.’ ” When Persin tried his finger prosthetic on someone, it looked “stupid” and like “Mickey Mouse,” and he spent a month correcting it. From then on, all her stages of decay were carefully designed up until the latter “Gollum” stage, where the look was designed with the use of plasteline (modeling clay) and an “old-school hand sculpt maquette.”

Because Fargeat wanted to use as few special effects as possible, even a scene in which Qualley’s Sue faces off with Moore’s Elisabeth is done with mostly puppets and only a small assist from VFX. “We made a dummy head of Demi with her Gollum face, which was quite sophisticated and could bleed and move realistically,” says Persin. “And then Margaret was really smashing the head on the mirror, causing the mirror to explode and break … then we were shooting the same scene with Demi, and the VFX department mixed the two shots so you can really see the fake head hitting the mirror, and then you could see Demi reacting.”

Moore would spend as much as six hours in the makeup chair depending on the transformation. The look that took the most work was the final one: Monstro.

Monstro, also known as Elisasue, is an amalgamation of Sue and Elisabeth after Sue tries to create a new version of herself using leftover serum. The result is a distorted blob, à la Edvard Munch’s The Scream, with what’s left of Elisabeth’s face etched into the monster’s back. “We sometimes disagreed. For the last stage, we understood each other,” Persin says.

Fargeat’s main concern on the film, he notes, was indeed the look of Monstro. But Persin’s first design — which used maquettes, digital sculpting and photoshop — came pretty close to the final version.

Monstro’s face, which took two hours a day to apply, was prosthetics, while its body was a suit. Qualley’s face was used for the close-up shots of Monstro, while a double stood in for the full body shots. “Nothing was too absurd,” says Persin. “It was never enough.”

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This story first appeared in a November stand-alone issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.