In preparation for their respective roles, Jake Gyllenhaal spent time with Jamie Reidy, the author of the book the film is based on, while Anne Hathaway spent time with Lucy Roucis, an actress stricken with Parkinson's disease, who has a role in the film.

At one point, director Edward Zwick jumped into bed with Anne Hathaway and Jake Gyllenhaal naked for a group shot to make them feel more comfortable. This shot was used for the film's poster, with Zwick digitally removed.

The anti-Parkinson's drugs Sinemet and Ropinirole mentioned in the film can cause sexual hyperactivity and hyperarousal in some patients as a side effect.

This is the second film that Jake Gyllenhaal and Anne Hathaway have starred in together. They previously played a couple in Brokeback Mountain (2005).

In setting up the sex scenes, the actors were encouraged to improvise, but with their clothes on. Edward Zwick says that it is "colder" on a set because there are people all around, the camera, and other distractions. Therefore, the improvisation was useful in setting the scenes and shots for the actual shoot.

The film is based on a book - Hard Sell: The Evolution of a Viagra Salesman - by former Pfizer representative Jamie Reidy. He says the book is a "jumping off point", and that there is no love interest in it, as he removed all of those references, thinking that his mother would read the book.

In designing the sex scenes, Edward Zwick had the principals watch romantic comedies and sexually charged films - everything from Pillow Talk (1959) to 9 Songs (2004) to Last Tango in Paris (1972) - and talk about what turned them on. Then some of those shots and ideas were incorporated into the making of the scenes.

Lawyers for both principals prepared documents about how much nudity the film would show. In the end, though, Edward Zwick simply pledged that there would be nothing in the film with which they were not comfortable.

Patti Podesta designed Maggie's loft to be in stark opposition to the cold, sterile, medical buildings, in which Jamie works.

Some of the clothes Anne Hathaway wears in the film come from costume designer Deborah Lynn Scott's own wardrobe.

When asked about the sex scenes, Jake Gyllenhaal joked: "I've had a pretty illustrious career at this point, but the hardest thing has been pretending to be turned on by Anne Hathaway. And I pride myself on really having pulled it off."

When asked about the nude scenes she performed in this movie, Anne Hathaway basically said that after awhile you may as well stop being shy and stay naked between takes or it will slow down production. "There is that revoltingly embarrassing moment when you have to take your clothes off in front of strangers. I mean, I don't go to the beach in a bikini for a reason. So I thought, 'OK, I'm going to be in control. I'm going to do everything properly, disrobe at the last minute, and in between shots get the clothes back on.' But then I found that every time I put my robe back on, it rubbed all the body make-up off, and that added 20 minutes to filming. As with all things in life, the second you stop making it about you and you make it about everyone else, it just got, dare I say, fun."

Anne Hathaway was so committed to performing the nude scenes in the film that one time she even got naked when she didn't need because the cameras weren't rolling. "I have to remove my trench coat and be nude underneath, and I thought we were filming," she said at the New York premiere of the movie. "But it turned out we were just rehearsing and I got unnecessarily naked in front of a lot of people!" Luckily at that point she was already used to the cast and crew seeing her totally nude so it was no big deal to her.

Anne Hathaway made an entire movie about the difference between physical and emotional intimacy. "These are people who have no trouble taking their clothes off -- in a way their bodies are their currency," she told Vogue about the character she played in Love and Other Drugs. "But they're terrified of exposing their vulnerability -- of becoming emotionally naked." It seems that, at least for Anne, the difference between the two is worth noting. If you can disconnect the emotional part of yourself from it, sex scenes might become a little more manageable. Of course, a little alcohol doesn't hurt either.

The television news presenter is the famous talk show Conan O'Brien.

In the movie the name of Anne Hathaway's character is Maggie, in real life Jake Gyllenhaal's sister's name is Maggie who is also a actress.

The last speaker (black hair woman) at the Parkinson Convention is Lucy Roucis who inspired the character Maggie Murdock played by Anne Hathaway in this movie.