The Substance's lead characters are two sides of the same person, aging star Elisabeth and her younger self, who dubs herself Sue.

The film is a dark comedy about the entertainment industry, but it's also quietly a tragic horror story about the lengths Elisabeth and Sue will go to achieve their ambitions, even at the cost to themselves. Steadily seeing each other as rivals for their shared time, the two sides of Elisabeth ultimately set up their own undoing. The themes of Demi Moore's arc in The Substance elevate the body horror comedy and add a personal level of tragedy and gravitas to the story. Here's how the ending of The Substance highlights the thematic core of the film.

Elisabeth & Sue's Final Transformation In The Substance's Ending Explained

The Monster At The End Of This Movie

The final transformation in The Substance is tragic and horrifying in equal measure and speaks to the overarching themes of the film. After killing Elisabeth, Sue initially believes that she's gotten a chance to fully live her life without the burden of her older self. However, her body quickly begins to fall apart without the serum. This leads her to try and reuse the one-use-only Activator serum, only for the resulting transformation to be a grotesque hybrid of Elisabeth and Sue. Notably, Elisabeth is resurrected by this, but only as a face trapped on Sue's body.

Seen by the public as a monster, Sue is forced to flee the New Year's show and is ultimately only able to make it so far before her body collapses upon itself and self-destructs. It's a melancholy turn in the film, with Sue more or less killed and Elisabeth reduced to a face with little time left. This transformation reflects the bitter side of Elisabeth and Sue that became increasingly prominent in the film, their physical form finally reflecting their monstrous choices. However, the film doesn't relish the transformation and instead paints them both as pitiful and tragic figures.

Why Sue Kills Elisabeth & What It Means

Sue's Final Fate Doesn't Go Well

A big element of The Substance is the mysterious company's repeated efforts to convince Elisabeth to see Sue as an extension of herself. However, as the film progresses, Elisabeth and Sue increasingly view each other as foes wrestling for control of the same life. This animosity builds until Sue decides to remain in control despite the repeated warnings of the fallout, resulting in Elisabeth being reduced to a haggard new form. When she finally does regain control, she tries to kill Sue. However, her own ego and horror at her actions result in her sparing her younger self.

However, upon awakening, Sue doesn't share that same mercy and ultimately kills Elisabeth. Thematically, this moment underscores how much Elisabeth has lost control of her desires and self-worth. Her younger ego outright killed her real self. In the plot, this ultimately proves to be Sue's undoing, as she quickly falls apart without Elisabeth around to safely provide the necessary serum for her continued existence. Thematically, by destroying her true self and assuming full control of her life, Sue quickly burns out and is transformed into the film's final monster.

Who Is The Supplier Of The Substance?

One Of The Film's Biggest Questions Is Never Answered

One of the underlying mysteries of The Substance is the identity of the organization that makes it. Elisabeth only hears about it from an unnamed nurse she encounters following a car crash, who believes she'd be an ideal candidate for the process. The inventor of the serum in The Substance remains a mystery throughout the Demi Moore movie, with the organization behind it only communicating through unseen phone calls or messages. Elisabeth picks up the serum from a dead drop in downtown Los Angeles, never communicates with anyone directly about it, and never learns who made it.

The film notably doesn't position the organization as the problem, however. They are blunt in their advice and appraisal of Elisabeth's increasing tensions with Sue, but don't try to convince Elisabeth one way or the other to abandon the serum. When Elisabeth contemplates ending the process, they explain the rules and leave the choice in her hands. Elisabeth and Sue's fate is decided by them and them alone. This underscores the film's themes about how Elisabeth and Sue's self-destruction is caused by their own decisions.

What Happens To Harvey & Pump It Up?

Harvey Represents The Predatory Aspects Of The Entertainment Industry

One of the biggest tragedies of The Substance is the lack of clear consequences for Harvey and the other producers who benefit from Elisabeth and Sue's suffering. Introduced as a slimy and misogynistic producer behind Elisabeth's workout show "Pump It Up," Harvey relishes getting to fire Elisabeth — inadvertently playing on her insecurities and pushing her to utilize the serum. Harvey's harsh attitude earns him accolades and a successful show thanks to Sue. Although his New Year's show goes down in flames, there's no indication he'll be blamed for it.

The themes of The Substance highlight how the entertainment industry can make people feel interchangeable, with a handful of cruel figures at the top dictating the careers and lives of others on a whim. There's no clear comeuppance for Harvey, whose final prominent moment in the film sees him and a group of similarly old rich white men ogling the young performers and telling Sue to smile. Harvey will likely find a new star for "Pump It Up" and suffer no clear consequences. It's a tragic reminder that predatory producers like Harvey still exist and succeed in Hollywood.

The Real Meaning Of The Substance

Elisabeth Becomes Her Own Worst Enemy

The true moral of The Substance is a tragic one, highlighting how someone can (literally) become their own worst enemy. Elisabeth is underappreciated and sidelined due to her age, despite decades of success and celebrity status. Although Harvey (a man whose age is comparable to her own) is at the height of his career, her age makes her a liability. However, he and the serum aren't what brings Elisabeth down. Instead, her own self-doubt, sense of inadequacy, and deepening self-esteem problems lead her to ignore her own beauty and potential.

Her attempt to get ready for a date but inability to go through with it illustrates this, a chance for self-acceptance and inner peace that she sacrifices in lieu of the iration of others. Sue's success forces Elisabeth further into self-loathing, fueling Sue's ambitions further. Their increasing mental divide turns two sides of the same person into bitter enemies. Elisabeth and Sue are their own worst enemy, and it leads to a tragic ending for both. The Substance is a powerful story that uses body horror to highlight how societal expectations can shape a person into an unrecognizable thing.

How The Substance Ending Was Received

Fans Were Split Over The Over-The-Top Ending

Critics love The Substance, awarding it an 89% fresh Rotten Tomatoes score, which makes it Certified Fresh. It also earned Demi Moore an Oscar nomination. However, audiences gave it a slightly lower 75% approval rating; part of that is the ending. One audience member wrote, "The last 20 minutes felt unnecessary and overly horrific. I expected the ending to reveal that the events were merely imagined—flashes in her mind before she decided to take the substance. Ending it this way would have made her character more powerful."

However, critics mentioned the ending as an important part of the story. Critic Peter Travers wrote for ABC News:

"For all it's shocking shifts into R-rated gore, "The Substance" is never less than a gripping takedown of the drug of youth obsession... Kudos to Moore who brilliantly seizes the role of her lifetime—her final showdown with Qualley is a bloody marvel with special effects that deserve their own awards attention."

Not everyone was happy with how The Substance ending wrapped up the story. In one Reddit thread, the OP wrote that the ending "ruined" the movie for them. They wrote, "I think they overdid it slightly with the blood going over and her face creepily moving over her star. The whole movie had a pretty serious tone, and the ending just did a complete 180." However, another person responded that they loved it for that reason, writing: "It almost felt like a celebration with beauty standards literally being ripped apart and splattered."