The original cut, which was screened at Sundance in 2013, was given an NC-17 rating by the MPAA. Writer and Director Joseph Gordon-Levitt cut some graphic porn footage that his character is watching throughout the movie from the final cut, which received an R rating. He chose to cut some of this footage, since he didn't want people to think this movie was solely about porn after being confronted with sexually graphic footage.
The film's original title, as advertised when it was shown at the Sundance and Berlin film festivals, was "Don Jon's Addiction". Joseph Gordon-Levitt subsequently decided to change it, because he felt that title put too much emphasis on the pornography storyline.
Joseph Gordon-Levitt is good friends with his Havoc (2005) co-stars Channing Tatum and Anne Hathaway, who make cameos in this film as a couple in a romantic comedy that Don and Barbara (Scarlett Johansson) go see. He is also good friends with his Looper (2012) co-star Emily Blunt, who can been seen, alongside her husband John Krasinski, in a movie poster in the movie theater scene. He is also good friends with his Inception (2010) co-star Leonardo DiCaprio, who you can see on the poster to Titanic (1997) in Barbara's old bedroom.
The only time you see Jon's sister is at the dining table and church with the family present. In those places too, she's always on the phone. Not until up to one hour 17 minutes into the film does she speak. That's also a small dialogue.