After being fired from her aerobics TV show on her 50th birthday, Elizabeth Sparkle (Demi Moore) takes a mysterious cloning serum (a Dolly mixture?) that creates a younger version of herself (a demi-Moore?).

Few could have predicted a body horror fairytale becoming this year’s Barbie; a feminist crowd-pleaser that hammers home its single gag with all the subtlety of a spandex bikini. There is a reason it isn’t called The Subtext (although The Substance is also generous), painting its toxic beauty standards messaging for the back row.

Coralie Fargeat (Revenge) has the guts to follow through on her grotesque vision of the lengths women will go to look younger, but botches the sci-fi concept. Rather than allowing the user to experience life in a younger body, the serum creates a separate consciousness (Margaret Qualley) who takes over Sparkle’s TV show while she lies unconscious in a toilet. She therefore has no motivation to continue with the Dorian Gray’s Anatomy trial, making it hard to invest in what little story there is.

Like the younger version of Elizabeth Sparkle (Liz Lemonade?), the film outstays its welcome, stretching its satire thin over 2+ hours. The gross-out moments have supposedly sent more people to the cinema toilets than those reheated hot dogs, but the movie (Being John Lycra Bitch?) is too unconvincing and cartoonish to be genuinely repulsed by its body horror. And for all its cinematic references (ranging from Species and The Shining to Carrie and The Elephant Man), The Substance is let down by the script’s on-the-nose job; insane in the membrane, inane in the brain.