The Mamma Mia! star sheds her clean cut image in Lovelace to portray the late porn legend, a part which was reportedly turned down by Olivia Wilde and Kate Hudson.
Seyfried admits she jumped at the chance to play the raunchy role - even though she worried it could signal the end of her working life.
She tells Britain's Daily Mirror, "I was like, 'Wow, this is the riskiest thing that's happening in Hollywood right now.' The first thing you think about is that it could ruin my career. At the same time I was like: 'This is my chance to show them, to show the industry, to be recognised.'
The actress reveals she found some aspects of Lovelace's life hard to deal with, adding, "It was a risky role to play, I suppose, but the nudity didn't scare me. I was more afraid of some of the violence and beatings she suffered, but she was a courageous woman and I've never been so affected by a role as I was by this.
"The story of Linda Lovelace's life is a very dark place to go. We couldn't show half of what she went through, although our film is still a pretty harrowing experience."