Demi Moore Broke Out in Shingles, Lost 20 Pounds Due to the ‘Intensity’ of Filming ‘The Substance’

Demi Moore had to suffer to draw out her career-best performance in “The Substance.”

A24 Published a Kids Guide to Watching Movies -- My Daughters Picked 'The Red Balloon' and 'Cats Don't Dance'

The body horror film that wowed at Cannes stars Moore as former A-list actress Elisabeth Sparkle, who opts to undergo a drug treatment to birth the perfect version of herself (Margaret Qualley). The film is written and directed by Coralie Fargeat.

Moore told the Los Angeles Times that while she balanced the co-lead part with Qualley, she actually got sick amid production.

“To give you an idea of the intensity, my first week that I actually had off, where it was just Margaret working, I got shingles,” Moore said. “And I then lost, like, 20 pounds.”

Moore continued, “You have to walk away feeling that you put it all on the table. It called for it and it’s what you want to bring to it.”

Moore previously told IndieWire’s Ryan Lattanzio that while her character does not have a “lot of dialogue,” the film is unprecedented in its “level of rawness and vulnerability.”

Martin Scorsese Is a Perfectionist Auteur in Meta Kith for Giorgio Armani Ad -- Watch

To the L.A. Times, Moore echoed that “The Substance” resonates due to its depiction of externalized self-sabotage.

“That’s what makes it such a powerful piece ,” Moore said about her character. “It’s really what she’s doing to herself that’s most violent. [The script] took something that is a very internalized violence against oneself and externalized it in this way that allows the audience to have a little objectivity and to then really see what we’re doing to ourselves through that harsh, constant criticism, and comparison.”

And it’s safe to say that Moore is proud of the feature that is being billed as her return to Hollywood.

She told Variety that after a producer on her film “The Scarlet Letter” deemed her a “ popcorn actress ,” she has been fighting against that typecasting. According to Moore, the label meant that she is “not a critically acclaimed kind of actress,” something that she has clearly shattered most recently with “The Substance.”

“It’s interesting, because that has stayed with me, holding that perception against myself,” Moore said. “ But there are a lot of my films that I don’t feel got any kind of consideration in that regard .”