Amanda Seyfried has revealed that portraying porn actress Linda Lovelace was "nerve-racking".
The Mamma Mia! star, who plays the Deep Throat actress in the big-screen biopic Lovelace, admitted that showing Linda's different sides proved to be quite a challenge.
"It was nerve-racking. It was like I was playing two different characters," she told the Hollywood Reporter at the film's LA premiere.
"In the beginning, she was this naive, idealistic young woman that was struggling with her family life and coming to terms with her sexuality, and the later years is when this woman really kind of came full circle. She's maybe contradicting how she felt when she was younger - we all do in our formative years. It's something you want as an actor."
The film, which was directed by Rob Epstein and Jeffrey Friedman, also stars James Franco, Peter Sarsgaard, Adam Brody, Sharon Stone and Chris Noth.
Jeffrey said: "The sexual revolution was a very important moment in our history; it sort of defined who we are, and it was a lot more complicated than I think people recognise, or than the mythology would have you believe. Linda's story is really about all of that.
"She's a very complex person who became the poster girl for the so-called 'sexual revolution', and then as she became more and more of a self-possessed woman and a feminist, she told a very different story about her life."
Rob added: "From the point of view today, where porn is ubiquitous and free and kids grow up with it, it seemed like an interesting moment to look at a time when we were just opening up to the possibility of mainstreaming porn. She was the genie."
Lovelace will open in UK cinemas on August 23.