14 Stars Who Stepped Into Their Characters’ Skin for Real

Sometimes it’s hard to believe how far actors will go to bring their characters to life. From extreme physical changes to enduring discomfort and learning new ways to move, these stars didn’t just play their roles — they lived them. And while we often see only the final, polished performance on screen, the real story lies in what they went through behind the scenes to get there.

Gwendoline Christie

Gwendoline Christie wanted the part of Brienne so much that she prepared for the audition for 6 weeks: she did kickboxing, yoga, and changed her diet completely. As a result, she lost 20 pounds. When she got the role, the workouts became even more intense.

But the biggest blow for the actress was the fact that she had to lose her beautiful hair. When she saw herself with short hair, she burst out crying and couldn’t stop for 2 hours.

Charlize Theron

For the role of a mother of 3 in Tully, Charlize Theron gained around 48 pounds. And it wasn’t the first time she gained weight for a role: for Monster (2003), she gained 30 pounds. But this time, Theron had to deal with unpleasant consequences.

First, due to a lot of unhealthy food and sugar in her diet, the actress had depression for the first time in her life. And second, she realized that at 42, it wasn’t as easy to lose weight as it was at 27. She didn’t sleep well, felt weak, and could barely walk on the treadmill. She needed 1.5 years of hard work and healthy food to return to her normal shape.

Jamie Foxx

For the role in the biographical film, Ray, Jamie Foxx met legendary singer and pianist Ray Charles. The actor is a pianist, so he easily got the approval of the musician. Foxx lost 30 pounds to look more like Charles, and his comedic experience helped him mimic the singer’s behavior.

But the greatest difficulty for the actor was portraying blindness. The director suggested Foxx become “blind” temporarily. 14 hours a day, the actor’s eyelids were glued together. At first, Foxx panicked and felt claustrophobic, but he got used to it over time, and it even earned him an Oscar.

Rachel McAdams

Rachel McAdams wanted to work with director Terrence Malick so much that she didn’t tell him she was allergic to horse hair and scared of the animals altogether. When he asked her if she was okay working with animals, she said she loved them. So when she was in To the Wonder (2012), her eyes swelled up and she could barely see anything.

Brendan Fraser

In The Whale, Brendan Fraser had to portray a man suffering from depression and overeating who, as a result, weighed 600 pounds. So, for the film, the actor would put on a suit and carry anywhere from 50 to 300 pounds of extra weight.

It was so exhausting that when the suit was removed, he would feel dizzy. He said that in order to carry the suit, he had to develop muscles he didn’t know he had.

Ana de Armas

For her role as CIA agent Paloma in No Time To Die (2021), Ana de Armas had to learn complex fight choreography and firearms handling despite having little prior action experience. She trained intensively for months to perfect her fluid yet lethal movements in her iconic action scene while maintaining elegance in a gown and heels. The physically demanding preparation pushed her out of her comfort zone, transforming her into a convincing action star.

Adrien Brody

For the role in The Pianist, Adrien Brody decided to change his life temporarily: he broke up with his girlfriend, left his apartment, sold his car, moved, and turned off all of his phones. To be more convincing in the role of Władysław Szpilman, Brody would play the piano 4 hours a day and starve. He lost almost 30 pounds, and he was already quite slim.

It was the hunger that gave him feelings of emptiness and desperation. For a year after filming, Brody suffered from depression. He went on to be one of the youngest actors to win an Oscar.

Austin Butler

To play Elvis Presley in Elvis (2022), Austin Butler didn’t just mimic the King’s voice — he transformed his body to match Elvis’s shifting physique over decades. Butler worked with a movement coach for months to master Elvis’s posture and dance style and underwent fluctuating diets to gain and lose weight to reflect Elvis’s physical changes. Even after filming, Butler admitted he struggled to let go of Elvis’s voice and body language, showing just how deeply the transformation impacted him.

Zac Efron

To show a powerful body with bulging veins in Baywatch, the actor had to undergo a very unhealthy experience. He would work out for hours and wake up at 4 a.m. to start his training. He ate only protein and leafy greens.

Because of this, Zac Efron developed a lot of health problems, including depression and insomnia. He realized that next time, he’d rather have a small percentage of extra fat than suffer for a good shot.

Jake Gyllenhaal

The events in Everest take place at 28,000 feet above sea level where people don’t have enough oxygen. To understand how it would feel, Jake Gyllenhaal, along with Josh Brolin, decided to try these conditions in a simulator.

They spent a little more time in the simulator than they had to because they liked how it felt. But 3 days later, they developed severe depression.

Matthew McConaughey

In order to lose 48 pounds for the role in Dallas Buyers Club, the actor needed the services of a diet expert. He tried to get Matthew McConaughey into the shape he needed in the healthiest way possible.

Instead of snacks, McConaughey would chew on ice and felt very energetic after losing weight — he even slept 3 hours less than usual.

Jennifer Aniston

In Cake (2014), Jennifer Aniston played a woman suffering from chronic pain. A couple of friends who had the syndrome of chronic pain helped her understand her character. The actress would wear a corset that would not let her round her shoulders, forcing her to walk with a straight back. 5 weeks after wearing the corset, the actress started to feel the pain herself.

And having to gain a few pounds didn’t upset her. She just stopped working out for a few months and stopped controlling her diet. She even enjoyed gaining weight.

Mabel Cadena

Mabel Cadena made a strong impression as Namora, the fierce cousin of Namor (Tenoch Huerta), in Black Panther: Wakanda Forever (2022). Some of the fantastic visuals of the film could only be accomplished with computer graphics. However, for simpler scenes underwater, director Ryan Coogler wanted his actors to really be submerged. This included dolphin kicks, freediving, and staying beneath the surface for long periods. Cadena was the best at holding her breath underwater, gushing about her six-and-a-half-minute record.

Also, Mabel had to sit in the makeup chair for six hours to become blue-skinned, and it took two hours to remove everything using a special vapor. Cadena laughingly said, “I have scratches in my skin from the color.”

Lady Gaga

For House of Gucci (2021), Lady Gaga didn’t just change her accent for the role of Patrizia Reggiani — she embodied her physical presence fully. Gaga stayed in character for 18 months, using the Italian accent for 9 months even off-camera, and adjusted her body language to reflect Patrizia’s controlling, confident demeanor. She wore heavy, vintage jewelry, helping her feel the weight of Patrizia’s persona and wealth. Gaga later shared that the physical transformation left her with psychological exhaustion, showing how deeply the character took over her body and mind.

It’s easy to admire a great performance, but knowing the sacrifices and dedication behind these transformations makes them even more impressive. Whether it’s mastering a walk in painful shoes or pushing through the mental strain of living as someone else, these actors proved that embodying a character is about so much more than memorizing lines — it’s about becoming someone else, inside and out.