You’ve got to admire the route Brat Pack diva Demi Moore is taking on her comeback path.

After a nearly catastrophic string of virtually unwatchable movies in the early part of the 21st century (with the possible exceptions of 2009’s “The Joneses” and 2011’s “Margin Call”), Moore has been roaring back with a vengeance via supporting roles in non-traditional movies beginning with 2022’s “The Unbearable Weight of Massive Talent” and, especially Amanda Kramer’s “Please Baby Please.”

For her first lead role in eons, as aging actress turned TV fitness guru Elisabeth Sparkle in Coralie Fargeat’s “The Substance” (Mubi), Moore goes the distance in ways few actresses would dare. After a particularly brutal lunch with repulsive network exec Harvey (a scenery-chomping Dennis Quaid, who in spite of becoming politically and religiously conservative in recent years, hasn’t lost his sense of humor), Elisabeth learns she’s aged out of her livelihood. But an encounter with an ER nurse following a car accident provides Elisabeth with an alternative. He slips her a flash drive with information about something called The Substance that promises her a better version of herself. 

Imagine, if you will, Robert Zemeckis’ “Death Becomes Her” co-directed by David Cronenberg and John Carpenter. That, in a nutshell, is the extreme body horror of “The Substance.” After reluctantly enrolling in the program, which involves a variety of injections and intravenous feedings, as well as the spine-splitting emergence of an “other self” (Sue as portrayed by Margaret Qualley) and a schedule to which she must strictly adhere (or risk the irreversible consequences), Elisabeth embarks on a terrifying journey of transformation, horror, violence, and degradation. Thinking she might experience some redemption (or revenge?), Elisabeth is thoroughly unprepared for what awaits her.

There is almost nothing I can say to prepare you for what you will see in “The Substance.” Visually original and startling, with Oscar-worthy make-up and special effects, my husband watched most of the conclusion through his fingers covering his eyes. If I wasn’t busy scribbling notes, I probably would have done the same. That said, and even though “The Substance” overstays its gruesome welcome by at least 30 minutes (there really ought to be a time limit for fight scenes!), it deserves to be seen for Moore’s performance.  

Rating: B