TORONTO – There are many, many shocking scenes in the new body horror movie “The Substance.” But for star Demi Moore, the most violent material was watching co-star Dennis Quaid wolf down shrimp with reckless abandon.

“Seeing that take after take? Disgusting,” Moore said with a laugh after a midnight screening of her film (in theaters Sept. 20) early Friday at Toronto International Film Festival.

A buzzy and genre-smashing look at age and beauty, “The Substance” stars Moore as Elisabeth Sparkle, a former actress and middle-aged TV fitness guru who's mocked for her “jurassic fitness” routine and forced out by her network boss (Quaid) in favor of a younger star. Elisabeth signs on for an underground process known as “The Substance,” which makes someone their most beautiful and perfect self. The result of that experiment is Sue (Margaret Qualley), who gets her own show that involves a bunch more twerking and gyrating.

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“I do dance, but I don't dance like that and I never will again,” Qualley quipped onstage alongside Moore and French writer/director Coralie Fargeat.

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The situation for both Elisabeth and Sue becomes more gonzo from there, and Qualley recalls the script being “so singular and evocative and crazy” the first time she read it. Moore’s first thought was the movie would “either be something extraordinary or it could be an absolute disaster,” she said. “That gave it the excitement of it being worth taking a risk, because it was also just such an out-of-the-box way of delving into this subject matter" and examining "the harsh way we criticize ourselves.”

Fargeat was last at the Toronto festival in 2017 with her action thriller “Revenge,” about a woman (Matilda Lutz) who is raped and then hunts down the three men responsible. After that film, “I felt in a stronger place" to express "what I wanted to say regarding what women have to deal with facing violence. And I felt strong enough to explore the next level,” the filmmaker says. “I was also past my 40s, and starting to feel the pressure ... that I was going be erased, that I'm going to be disappearing. And I felt like I really wanted to kind of say a big scream, a big shout, that we should make things different and we should try and free ourselves from all this pressure that leads to being willing to express all the violence.”

It was important for Fargeat that “The Substance” presented violence and gore from the female perspective. Horror movies “tended to be very gendered when I grew up as a little girl. Those kind of movies were for the boys, what the guys were watching. And to me, when I was watching those movies, I felt I was entering into a world that I was not supposed to be (in), and it was super-exciting.

“When I was little, boys were allowed to do so much more stuff than a girl was allowed,” the director adds. “The idea of being feminine, to smile, of course to be dedicated and gentle: To me, those kind of films when I grew up were really a way to totally express myself.”