To make Jennifer Aniston look more worn down, director Miguel Arteta made her wear wrist weights for several weeks prior to filming; she also wore them during some of the scenes.
According to Jennifer Aniston, from the first draft of the script to the shooting, almost no changes were made.
Outside of Friends (1994), at the time this was Jennifer Aniston's most critically acclaimed performance. Many thought she might even secure an Oscar nomination but she missed out.
Jake Gyllenhaal admitted that in the film's sex scenes, his main job was to lie over Jennifer Aniston and keep her breasts covered. He said she also put a pillow between them so there wouldn't be any touching of their lower areas.
Jennifer Aniston trusted director Miguel Arteta to stop her the moment she did something similar to her Friends (1994) role. She would jokingly say to him, "Please don't let her be Rachel."