Katherine Heigl Admits 'Grey's Anatomy' Success Made Her 'Mouthy'

American actress Katherine Heigl opened up about her time on the hit medical drama series "Grey's Anatomy" and how the show's immense success affected her personally and professionally.

Heigl, who portrayed the beloved character Dr. Isobel "Izzie" Stevens, revealed that the show's popularity gave her a "false sense of confidence" that led to her becoming more outspoken, sometimes to her detriment.

She notably left the show amid heightened controversy in 2010 as she alleged that the working conditions were gruesome and called her character on the show a "rating's ploy."

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"Grey's Anatomy," created by Shonda Rhimes, became a cultural phenomenon since its premiere in 2005. Heigl quickly rose to stardom and received critical acclaim for portraying the talented and ambitious Dr. Stevens. However, behind the scenes, her actions began to generate headlines, leading to speculation about her reputation in the industry.

During a recent Variety Actors on Actors interview with her "Grey's" costar Ellen Pompeo, Heigl, 44, acknowledged that the immense success of the medical drama series played a significant role in her attitude at the time.

"I think that gave me this confidence that was a false sense of confidence. It was rooted in something that couldn't and maybe wouldn't always last for me," Heigl said. "So then I started getting real mouthy because I did have a lot to say, and there were certain boundaries and things that I was not OK with being crossed."

The actress gained a reputation for speaking her mind and publicly expressing her dissatisfaction with certain aspects of her career. Notably, Heigl famously withdrew herself from Emmy consideration in 2008, citing a lack of substantial material in the show's writing and her character, Dr. Stevens, not having enough development.

Heigl's candid remarks during interviews and press events ultimately led to strained relationships within the industry and negative perceptions among the public. The actress reflected on this period to Pompeo, admitting that her controversial outspokenness was partly due to her naivety.

"I was so naive. I got on my soapbox and had some things to say, and I felt passionate about this stuff. I felt strongly," Heigl said. "I felt so strongly that I also got a megaphone out on my soapbox."

She added, "No part of me imagined a bad reaction. I felt justified in how I felt about it and where I came from."

The "Life as We Know It" actress previously opened up about feeling "betrayed" when the public and industry seemingly turned against her following controversial comments she made about her past projects, including the hit television series "Grey's Anatomy" and the film "Knocked Up."

An example of such a controversial comment was made in a now infamous interview with Vanity Fair when she called her "Grey's Anatomy" character arc a "rating ploy" and said that "Knocked Up" was "a little sexist."

"I'm not the only person in the industry who's had ups and downs, but it's like, as soon as things were going too well, there was this need to say, 'Slow down there — let's humble her,'" she shared in an interview with Red magazine in January.

Heigl continued, "I felt betrayed. I wondered, 'How could they turn on me so quickly? I'm just trying to entertain people.'"

In her interview with Red magazine, Heigl disclosed that she regretted apologizing for her controversial comments about "Grey's Anatomy" and "Knocked Up." The actress admitted her countless apologies did more harm than good because "it made me weaker in people's eyes."

She claimed that by constantly apologizing, she only managed to keep the issue alive, which only worsened the situation, admitting that she should have only apologized once.

Heigl elaborated on her change of heart, stating, "I kept apologizing, which I now realize just kept giving the whole thing a heartbeat. I thought self-flagellation in front of everybody would make them happy, but it made me weaker in people's eyes and weak. I now think that one apology was enough."

The actress emphasized that she'll "always stand up for things I believe in" but noted that "airing dirty laundry is unnecessary and will just fuel gossip."