Seyfried delved deep into her character in the biopic "Lovelace," which premiered this week at the Sundance Film Festival. The 27-year-old actress says she was only able to shed the dark role by playing Cosette in the Oscar-nominated "Les Miserables."
"I had a hard time letting go of Linda at the end of the movie," she said. "I had a really intense time with (co-star) Peter Sarsgaard. I think we both had a hard time letting go because we went to these places.
"He played a man who consistently beat his wife. And I played a woman who was raped and abused, psychologically and physically. I was constantly taking my clothes off. I didn't have an issue with that. She had an issue with that. So it was a lot. And the only thing that helped was getting onto `Les Mis.'"
"Lovelace" tells the story of the unlikely porn star and the abusive relationship she shared with her husband, Chuck Traynor.
Seyfried was grateful her musical part in "Les Mis" came just three weeks after "Lovelace" wrapped.
If not, she said she might have "carried Linda for a long time, and it could have been unhealthy," even though she knew from the start the role would be risky - and risque.
"It is risky and people did not stop reminding me of that. But I also really wanted a challenge. It appealed to me in that way," she said. "And this woman had a fascinating story. There are things that a lot of people don't know. People have an idea of her. It's very one-dimensional."
Directed by Oscar-winning documentarian Rob Epstein and Jeffrey Friedman, "Lovelace" was based in part on Lovelace's memoir, in which she recounted her entrance into pornography as the star of "Deep Throat," which brought porn to mainstream audiences.
Seyfried said Lovelace was "exploited."
"She was coerced into the porn industry," said the actress, who was accompanied by her mother at Sundance. "Yes, she enjoyed parts of it because parts of it made her feel safe because she was around so many people. But there's so much to say."
Born Linda Susan Boreman, Lovelace died in 2002, but Seyfried spoke to two of her children as part of her research. She said that while she doesn't feel like she has much in common with the pioneering porn star, there are similarities.
"Being in the public eye now, people can make assumptions about me, I'm sure. And no one really knows what's really going on. So I can relate in that way," Seyfried said. "She comes from a place of innocence. And I definitely did as well at one point coming into this business, which is nothing like the porn industry. People try to exploit me all the time. You've got to know your boundaries and you've got to know how to speak for yourself. But unfortunately she didn't have that freedom like I do. She had a husband that literally wouldn't allow her to go to the bathroom without asking."
Seyfried said she took "the responsibility very seriously of portraying and giving her validation and being her voice," especially after meeting her children, "which is why I was so nervous about releasing it into the wild."
Still, she's delighted the film premiered at the annual independent-film showcase.
"I just am so, so happy and proud to be able to say that this is our premiere," she said. "It's here and it feels safe here almost for some reason, I don't know why. Maybe because it's just really cozy and everybody is really friendly."
But she acknowledged she's still frightened about how the film will be received when it reaches a wider audience. Earlier this week, it was acquired by the Weinstein Co.'s Radius label for North American distribution for a reported $3 million.
"It's scary. I'm really scared," Seyfried said. "I don't know what's going to happen after it comes out. But I would never take it back. I'm really happy that I was able to give her the voice that she never got to have."
(Copyright 2013 by The Associated Press. All Rights Reserved.)