‘Tulsa King’ Star Max Casella Reveals He Didn’t Reach Puberty Until 27 Due to Pituitary Dwarfism: ‘It Was a Horror Show’

Real talk. Tulsa King star Max Casella opened up about his pituitary dwarfism diagnosis — and how it kept him from hitting puberty until he was 27 years old.

"I was given testosterone," Casella, now 55, told Page Six on Wednesday, November 9. "I was on growth hormones; I'm still on those things. My body didn't go through the change by itself."

The Newsies star explained that because he has a “malfunctioning pituitary gland from birth,” he was forced to “jumpstart my own puberty” by getting pumped “full of testosterone and growth hormones” in order to grow.

He noted, “I was 25, and I hadn’t even shaved."

Pituitary dwarfism is when the pituitary gland fails to produce an adequate supply of growth hormone which is essential for normal childhood development, according to Johns Hopkin's Medicine — and is something that Casella referred to as "a horror show."

"I couldn't talk about it. No one understood it,” he told Page Six on Wednesday. “It's like the trans community today talks about body dysmorphia and feeling like, 'I'm in the wrong body,' absolutely my experience. Absolutely. I was a man trapped in a little boy's body throughout most of my 20s until they finally pumped me full of testosterone."

While the Washington D.C. native admitted that delaying puberty allowed him to land roles meant for younger actors — he was cast as 16-year-old Vinnie on Doogie Houser M.D. at age 21 — it was still a challenge, especially at such an impressionable age.

Now, Casella is gearing up to star in Parmount+’s new series Tulsa King alongside Sylvester Stallone. While Casella has acted in a multitude of blockbuster films — including Newsies and Sgt. Bilko, in which he starred opposite Christian Bale and Steve Martin, respectively — the Good Fight alum still referred to working with Stallone, 76, as an “almost s–t in your pants moment.”

“I had his poster on my wall when I was 10 years old, and now I’m acting with him? It’s surreal,” he gushed to Page Six. “I’ve acted with a lot of big stars: Leonardo DiCaprio, Brad Pitt, Johnny Depp. Sometimes it’s up or down, your experience with them, but nobody like Sly, who was such a superhero to my 10-year-old self. This was like my boyhood dream.”

Despite his jitters, Casella shared that his experience with the Rocky star couldn’t have been a more pleasurable. “He made me feel comfortable because at his core, I think he’s a blue-collar guy. He’s got a blue-collar work ethic, and he respects hard work,” he added.