Depending on which commercials you've seen for this movie, you may not realize that Anne Hathaway's character has early-onset Parkinson's disease. It's not a secret, except in the sense that the studio apparently didn't want to scare away audiences -- she mentions it the first time we meet her, and it's a constant talking point throughout the film. But that's only one of three different movies going on here. The second movie is an insider's look at the drug industry, specifically the tactics used by drug reps to get their drugs into doctors' hands, or at least their eyeline. And the third movie is a raunchy Judd Apatow comedy. Any two of those movies would have been plenty, but three causes way too many tonal shifts, and it gets a little hard to figure out how you're supposed to be feeling at any given time.
Jake Gyllenhaal plays a serial womanizer and medical school dropout named Jamie, who can sell stereo equipment to anyone with a vagina, much to his doctor parents' chagrin but gets a job selling pills for Pfizer when he nails the wrong co-worker. After indoctrination camp, he's sent to the suburbs of Illinois, where he actually pays an indifferent doctor (Hank Azaria) a thousand dollars to be able shadow him and basically sing his products' praises all day. That, of course, is where he meets Maggie, who for some reason does not press charges, but instead agrees to coffee and a quickie. She may have a thing for hot guys who impersonate doctors, but mostly she's just trying to forget the mass amounts of medication she takes each day to keep her disease in check. That plotline keeps going down a very dull road. Lust becomes love, Maggie distances herself, they accept it, Jamie suddenly wants to cure her disease, etc. It eventually turns into a pretty sappy sick-person-movie cliché, which we've seen a dozen times before.
The medical-industry stuff is slightly more interesting, with particular attention to pharmaceutical rep rivalries, the hazards of owning your own practice, seniors getting bussed to Canada and the side effects of Viagra, but none of it actually goes anywhere; it's mostly just color taken from the non-fiction source material to show what that world is like. And the raunch is almost entirely delivered by Jamie's little brother Josh (Josh Gad), an Internet start-up millionaire, who's sleeping on Jamie's couch for some reason as he and his wife go through a rough patch. It's Josh who makes most of the jokes about Jamie and Maggie having sex (which we see a lot of) and generally engages in a variety of lewd behavior. It serves to break the tension, but, juxtaposed with Maggie's illness and the psychological damage displayed by both her and Jamie, it can also be a little uncomfortable, especially when he starts pleasuring himself to their sex tapes. Wrong, right? It's a little bit wrong. But the wrongness doesn't do enough to shake the movie out of familiar rom-com territory, it just puts it in a weird kind of limbo, where you're watching a rom-com, and you know what's going to happen, but you're not sure who to root for or what to laugh at.