The actress appears in several sex scenes with her co-star Jake Gyllenhaal in the film and has to show a lot of flesh, but one day on set she got nude in front of the crew for no reason.
She said: "On the day I shot the scene where I have to remove my trench coat and be nude underneath I thought we were filming, but it turned out we were just rehearsing and I got unnecessarily naked in front of a lot of people. But hey, I just did my job."
Although she seemed confident on set when she wasn't wearing any clothes, Anne insists she was full of butterflies inside.
Speaking at the premiere of 'Love and Other Drugs' in New York City, she said: "I didn't let anyone know that I was nervous. It was just an internal thing."
The 28-year-old screen beauty was recently praised by Jake for her natural "rhythm" during the lovemaking scenes.
The 29-year-old actor - who also 'romped' with the actress in 'Brokeback Mountain' - said: "Annie and I had already had sex on film in 'Brokeback Mountain', so I wasn't too nervous. There's something about the way Annie and I both work which is inherently very musical. It's all about rhythm. There's a rhythm to writing, there's a rhythm to sports and there's a rhythm to sex."
In the film, Jake plays pharmaceutical salesman Jamie Randall who ends up bedding Maggie Murdock, portrayed by Anne, when he tries to sell her a sex-enhancement drug for men.
