Demi Moore's Trauma Over Stripping and Transforming for Nightmarish Body Horror 'The Substance': 'It’s About Rejection'

Demi Moore really sunk her teeth into her role in The Substance.

In the body horror film, the Hollywood icon, 61, plays Elisabeth Sparkle, an aging television host who takes a wild new beauty method to make her look younger.

However, in order to show the ways in which her appearance changes properly, Moore had to spend hours in the makeup trailer, RadarOnline.com can reveal.

"The transformation that takes place is really dramatic," the G.I. Jane actress revealed in a recent interview. "It's not glamorous. I'll warn you. The script required a real level of vulnerability and exposing oneself in a raw sense, because it's about addressing feelings of rejection and lack of place and belonging. Things I think we can all experience."

After decades in Tinseltown, Moore has a vast awareness of the pressure women are under to look a certain way. "I was able to step into that and really let those parts of myself be seen," she added.

Luckily, the mother-of-three feels that the industry has come a long way. "I think streaming has a lot to do with that. We see a lot more content that is highlighting talented women," Moore explained.

She added: "How do you navigate it? You just show up and face what's in front of you to the best of your ability. I think what's more important is how you hold yourself, not how the world is holding you."

The A Few Good Men actress admitted she went to great lengths to be in tip-top shape. "I was feeding her through the night, getting up in the dark with a trainer … biking all the way to Paramount, even on location where we were shooting; then shooting a full day, which is usually a 12-hour day; and then starting all over again," Moore recalled during a recent interview with CBS Sunday Morning about her regime while filming Indecent Proposal.

"I think (Scout) was, like, five or six months old when we were shooting," she added of the 33-year-old.

"I put so much pressure on myself," the matriarch noted. "I did have experiences of being told to lose weight. And all of those, while they may have been embarrassing and humiliating, it's what I did to myself because of that."

Looking back at the hurdles she used to jump through in order to stay thin, she added, "Even just the idea of what I did to my body, it's so crazy, so ridiculous."

As RadarOnline.com previously reported, Moore admitted how mean she was to herself. "What I did to myself. What I made it mean about me. Really looking at that violence, how violent we can be towards ourselves, how just brutal," she revealed in a separate interview.

"We've all had moments where you go back and you're trying to fix something, and you're just making it worse to the point where you're incapacitated. We're seeing these small things nobody else is looking at, but we're so hyper-focused on all that we're not," Moore explained. "All of us, if we start to think our value is only with how we look, then ultimately we're going to be crushed."