Spoiler Alert: We’re diving into key plot points and the ending of The Substance, now in theaters, so proceed with caution if you haven’t seen it!
Margaret Qualley proves she can transform into a true monster when the role demands it. In The Substance, Demi Moore plays an aging fitness icon who turns to a black-market drug to regain her youth. Yet it’s Qualley, in the film’s shocking finale, who dons an elaborate prosthetic suit to embody a creature that is both grotesque and oddly beautiful.
“It was torture,” Qualley recalls, crediting her talented team of prosthetic artists for their support during the grueling process. “They helped me through the day and managed to make me laugh while I was on the brink of panic.”
In The Substance, Moore’s character, Elisabeth Sparkle, faces the harsh reality of being pushed out of her job by her sleazy boss (Dennis Quaid), who seeks a younger replacement. Desperate, Elisabeth undergoes a risky transformation, resulting in a new self—Qualley’s character, Sue. The twist? They must share one existence, alternating weeks in their respective bodies.
Sue, initially a hit on air, revels in her newfound fame and begins to break the rules, stealing extra “Stabilizer” fluid from Elisabeth’s spine. As Sue indulges, Elisabeth’s body starts to wither, leading to a clash between the two. When Sue runs out of fluid, Elisabeth contemplates a “Termination” serum but hesitates, only to face dire consequences.
The chaos culminates in the emergence of Monstro Elisasue—a bizarre hybrid that embodies both women. Qualley finds a touching moment in Monstro’s character as she adorably puts on an earring, despite the surreal sight of Elisabeth’s screaming face protruding from her shoulder. “It was a beautiful moment of love and gooeyness,” Qualley reflects. “Monstro is kind of gorgeous in her own way.”
To transform into Monstro, Qualley endured six hours in the makeup chair, rendering her nearly immobile. “I could only see out of one eye, couldn’t hear, and had huge retainers,” she explains. “It was grueling to embody, but the character’s purity was refreshing after playing the more soulless Sue for months.”
Moore adds that the experience is more complex than it appears on paper. Once the prosthetics are applied, eating and drinking become nearly impossible, demanding strict discipline.
Monstro takes center stage in the film’s wild finale during a live New Year’s show, where chaos ensues as blood explodes from her body, covering the audience. “We used 30,000 gallons of fake blood,” Qualley shares, mentioning that writer/director Coralie Fargeat even operated a firehose to enhance the mayhem. Moore humorously notes, “That was the only week I had off—and I got shingles!”
Though Monstro doesn’t achieve a traditional happy ending, escaping but exploding over Elisabeth’s star on the Hollywood Walk of Fame, Qualley’s experience with the character left a lasting impression. “Wearing the Monstro suit caused acne that lingered for six months after filming,” she reveals. “But honestly, I kind of loved how it looked, so it was okay.”