17 Behind-The-Scenes Secrets You Probably Never Knew About How Gruesome Body Horror The Substance Was Made

If you’ve seen The Substance in a cinema over the last week, the chances are you’re still thinking about some of the film’s more extreme moments, mulling over the amazing performances from Demi Moore and Margaret Qualley or perhaps just trying to wrap your head around exactly what it is you just watched.

But if you’re anything like us, you might have also been pondering exactly how such a uniquely stylised film – with all of its stomach-churning body horror and physically demanding sequences – came to be.

Well, you need wonder no more. From the script to the screen, here are 17 behind-the-scenes facts you probably never knew about how The Substance actually got made…

First of all, director Coralie Fargeat fully never expected Demi Moore to say yes when she first sent her the script 

“To be honest, when her name came up, you know, when we were thinking about actresses, I said, ‘Oh, forget it. She will never want to do something like that. Let’s not lose time, you know’,” Coralie admitted to People magazine at the initial premiere of The Substance.

“And then I said, ‘Well, we have nothing to lose. Let’s just send the script’.”

And it’s a good thing she did, because we truly can’t imagine any of Demi’s peers playing Elisabeth Sparkle quite like she did.

Lead actors Demi Moore and Margaret Qualley already had a bit of a connection before they were cast

Of course, Demi worked with Margaret’s mum, Andie MacDowell, almost 40 years ago in St. Elmo’s Fire.

However, there was another connection, as Margaret was also friendly with the Ghost star’s children, Rumer, Scout, and Tallulah Willis, so before they were even on set, she told People “we felt like we knew each other”.

In keeping with the types of films that inspired it, Coralie was keen to rely mostly on practical effects rather than computer trickery, CGI or AI

“I would sometimes suggest we use VFX and she would immediately say no, because she doesn’t like VFX,” prosthetics designer Pierre-Olivier Persin told GQ.

“It’s really a movie about our bodies and about the reality of how we feel in our bodies. I needed to speak to the reality of the way our flesh can reflect our mental deformation, and I knew this had to exist for real,” she told The Hollywood Reporter.

One of the film’s only bits of CGI came at the end, when Demi Moore’s screaming face was added to the back of Monstro Elisasue, a character who was otherwise achieved entirely with prosthetics.

Meanwhile, realistic dummies were also constructed to help with the “birthing” scenes.

“We had quite sophisticated silicon dummies. We had two for the birth. We also had matching prosthetic makeup on the body double and some days we applied the makeup on Demi,” Pierre-Olivier told Marie Claire.

One thing that wasn’t real was the film’s Hollywood setting, though 

Coralie explained to Rue Morgue: “We shot 100 percent of the movie in France.Cinema, to me, is the art of illusion, and that’s what I really enjoy when I make my films, to be able to cheat stuff.

“So the house was entirely shot on a set, on a stage. A huge part of our prep was deciding how we were going to recreate the view of Hollywood [from Elisabeth’s large window]. It was a major research-and-development thing, thinking about different techniques and finally using the one that would give the most life and the greatest sensation of being inside the location.”

She added that rather than recreating a “realistic” Hollywood, she wanted to “create my version of Hollywood, the one that we all have in our unconscious minds”, putting together a “kind of enhanced vision of Hollywood that fit the story”.

Demi Moore’s prosthetics journey took her character through five different stage, with each part having its own nickname

These were known – pretty self-explanatorily – as “Requiem” (inspired by Ellen Burstyn’s character in Requiem For A Dream), “The Finger”, “Gollum”, “Monstro” and “Gremlin”.

Before Elisabeth’s decline begins, Pierre-Olivier admits that he and Coralie clashed over how the character should look.

“I had a bit of a fight with the director because I told her that she had to be beautiful in the beginning,” he revealed to Marie Claire.

“It had to be like, ‘Why would they [fire her]?’ Because she has everything, she’s beautiful, she still has a show that’s going on very well – so I wanted for her to be sparkling and beautiful.

“Coralie was telling me, ‘No, no, no, she cannot,’ and I said, ‘Coralie, I have to have the time for her to go down deep before she has all the prosthetics and all of that’.”

If you’re wondering, all those prosthetics could take Demi Moore as long as six hours to put on

And then another two hours to take them off without doing any damage to the actor’s skin which, in the middle of a tightly-scheduled film shoot, is pretty important.

Margaret Qualley really struggled with her own prosthetics

“It was torture,” she told USA Today. “I had this awesome team of prosthetic artists that put it on me and took it off of me and got me through the day and made me laugh a couple of times while I was just on the brink of panic.

“I only have one eye. I can’t hear anything. I can’t move my arms. I’ve got these retainers in that are like too huge, they just kind of cut everything. It was grueling to embody.”

She added to The Times: “It was a torture chamber. The amount of videos I have of me like, ‘I can’t do this anymore.’ It was eight days. I know that doesn’t seem like a lot.

“We would just go until I had a panic attack. And the tempting thing is you want to peel it off, but of course you can’t do that, because you’ll bring your skin with you.”

Oh, and Margaret Qualley was also wearing prosthetics you mightn’t have even known were there

According to Margaret, Coralie Fargeat had envisioned Sue as a curvaceous “Jessica Rabbit”-type.

“Unfortunately there is no magic boob potion, so we had to glue those on,” she told The Times. 

“Coralie found an incredible prosthetic team to endow me with the rack of a lifetime, just not my lifetime.”

Yes, Demi Moore and Margaret Qualley really did have to learn all those aerobics routine

Margaret described her own dance sequences as “brutal”, and later admitted she needed a bit of liquid courage to get through the day.

“I just got wasted first thing in the morning because I was like, I can’t do this in front of everybody,” she told The Times, claiming a combo of tequila and weed helped her through that difficult day. 

For Demi, the most difficult part was the infamous scene in front of a mirror

After setting up a date with an old school friend, Elisabeth is about to head out for the evening, when she becomes distracted with thoughts of Sue, and repeatedly removes and reapplies her makeup.

“It was very difficult,” Demi told Variety, describing the scene as “one of the most heart-wrenching moments in the film”.

Apparently, Coralie required as many as 45 takes for the shot, (15 for each of the three makeup set-ups), until it reached “a point where I couldn’t do it anymore”.

In fact, Demi said, it was actually the make-up team who intervened, which Pierre-Olivier confirmed to be the case to Marie Claire.

“My concern was she’s going to hurt herself. At the end, I did something that I never did on a movie, ever. I told Coralie, ‘That’s enough. You cannot do it anymore because she’s going to have a rash all around the face’,” he recalled. 

“Coralie said, ‘Yeah, yeah, yeah, okay, okay, no problem.’ But of course after the 11th [take], she said, ‘We are going to do it once again,’ and I took the remover pad and I squashed everything, and I said, ‘I removed everything, that’s over. You have already 11. You cannot have more because tomorrow she will have a red face.’”

“Normally you don’t do that! But it was too much because it was very hard on her skin,” he revealed.

All that hard work really did take its toll on both Demi and Margaret

Demi told the LA Times that for the week of shooting where she wasn’t needed on set, she ended up contracting shingles – “and I then lost, like, 20 pounds”.

For her part, Margaret said that eight days on set wearing enormous prosthetics led to her breaking out in “crazy acne for a full, long-ass time”, the effects of which she claimed could still be seen in her other 2024 film Kinds Of Kindness.

Despite all of the body horror in The Substance, Demi had a surprising choice when naming the ‘most violent’ moment of the film

Apparently, she still crings every time she sees Dennis Quaid eating all of that shrimp. And if you’re wondering, he ate it all for real, with Coralie estimating the actor probably ate around “two kilos” of shrimp while filming.

“I will just warn everyone, the scene with Dennis [Quaid] eating the shrimp is by far the most violent scene in the whole movie. He ate, I think, four pounds of shrimp, tearing the heads off with sound effects,” Demi recalled to Seth Meyers, while gagging.

Dennis Quaid was actually a late addition to The Substance

He took over the role of Harvey from Emmy winner Ray Liotta, who was cast in the film in 2022, but died before filming got underway.

And his character’s name, Harvey, was no coincidence either

“Not at all!” Coralie said with a laugh when asked by Rue Morgue if the reference was unintentional. “To me, that’s part of the craziness of filmmaking – how with just a first name, you can characterise a whole type of person.

“It says so much about those stories that we heard everywhere, and then that kind of exploded with this specific figure, and now just this name, Harvey, can represent something that has existed in society on many different levels.

“I love to work with symbolism, and the symbolism of that name was definitely powerful and strong.”

But what about the other characters’ names in that case?

“For Sparkle, it was this idea to shine, to be under the light, and to have this moment that means happiness,” Coralie told Collider.

“‘Elisabeth’ – I don’t know why it came that way, but probably because it had this iconic resonance of all the big movie stars in the past.

“I remember at some point, somebody tried to make me, in production, maybe, change the name because we didn’t want to have legal issues, or I don’t know why. I said, ‘No. No way’. I don’t know. I knew this name was important.”

Interestingly, Coralie said she picked Sue as she felt it had an air of youthfulness, while Margaret pointed out that it also made the speaker make a sexualised mouth shape when saying the character’s name.

Let’s talk about that shower of blood in the finale, shall we?

“It was like a fire hose. It’s like what the firemen are using to put fire down; it was the same stuff with blood,” Pierre-Olivier told Marie Claire.

“I knew the scene needed to be massive,” Coralie also told Entertainment Weekly, estimating around 36,000 gallons of fake blood were used, which she said was essential “because the movie is about flesh, blood, and bones”.

And since we’ve gone this long without mentioning it – yes, those nude scenes were the real deal, and yes, that made things a little awkward on set

“We had to do these moments of switching, on this cold tile floor, and we’re both nude and laying there. There’s an aspect of it that was so absurd and funny,” Demi told Entertainment Weekly.

“Knowing that we had each other, looking out for each other, it’s just impossible not to find the absurdity of it humorous. At some point, I said, ‘Thank God we like each other, because otherwise this would be really awkward!’”

The Substance is in cinemas now.