Since its Cannes premiere “The Substance” has churned controversy over its body horror scenario, frequent, flagrant nudity – and buzz about a Best Actress Oscar nomination for Demi Moore.

Elisabeth Sparkle, Moore’s telegenic exercise queen, is fired the day she turns 50. Desperate and depressed, she opts for a mysterious black market procedure known only as the Substance which promises a younger, better version of herself.

For one week, perky, young Sue (Margaret Qualley), born out of her own body, replaces Elisabeth. Exactly seven days later the exchange must be repeated. Things do not go well.

“It’s a really important subject matter, dealing with aging and our value of self,” Moore, 61, said in a Zoom interview. “And it’s being told in such a unique way.”

As to what why it resonates, “The overarching theme is to our value as we age. Most importantly for me, the takeaway was really about the violence that we hold against ourself. The value that we give to other people’s opinions of us.

“My hope is (viewers) will take a reframing of our self love, self appreciation and self worth.”

“I can piggyback on that, having played Sue,” Qualley, 29, added. “Sue is meant to embody an idea of perfection. But it’s a totally soulless character. Until she turns into the ‘monster’ — and experiences love for the first time.”

“There’s so many things in this,” Moore said. “Like the idea of a rivalry between young and old, which is, again, the fight that we can have within ourselves, depending on what we’re making important, what we’re giving meaning to in our life.

“At the same time, there is the setting” – a workout studio – “which is dealing with the ideal. Like the male perspective of the idealized woman that we as women have bought into.

“Also fascinating is: I get this younger body, this revived second chance. Yet I fall into the same pattern, seeking the same approval.

“It’s that idea of when we chase perfection, we sometimes lose the very essence of the beauty of what we started with.”

As for the extensive, matter-of-fact nudity, “In this film, it’s not nudity for nudity’s sake. It’s really about the vulnerability that is felt when we are exposed. This isn’t sexualized nudity.

“If you look at it, most of our scenes are alone. It’s what that experience is when we’re alone with ourselves. The way in which we can dissect, look and explore without someone else watching.

“We live in a country where a lot of shame is attached to nudity,” she concluded.  “Even the focus being placed on the nudity here? When, for me, it’s the least important part of what we’ve done.”

 “The Substance” is in theaters Sept. 20