THE studio bills Jake Gyllenhaal and Anne Hathaway’s Love & Other Drugs as an unconventional love story.

Maybe a bit, in its unusual setting, the world of prescription drug sales, and in its attempt to inject drama by arbitrarily giving an incurable disease to one of its romantic leads.

Yet despite its dramatic pretences and far racier sex scenes than the typical studio romance, the movie is as predictable and ultimately as sappy as any other run-of-the-mill Hollywood love story.

Gyllenhaal and Hathaway, who co-starred as a couple in a sinking marriage in Brokeback Mountain, look and feel right in each other’s arms, sharing a relaxed bond that makes you think, here are two people who belong together.

Co-written by director Edward Zwick and producers Charles Randolph and Marshall Herskovitz, the screenplay shoves the two together awkwardly — and keeps them coming back together even more awkwardly — undermining the easy, genuine sense of affection and passion the stars manage.

But awkwardness seems to have been there from the start in creating a screen adaptation of Jamie Reidy’s book Hard Sell: The Evolution of a Viagra Salesman, which was not a romance at all.

Gyllenhaal’s Jamie Randall is a suitable stand-in for Reidy’s slick, aggressive master salesman of pharmaceuticals in the late 1990s, when Viagra first came on the market. Hathaway’s Maggie Murdock is a complete fabrication, however — a love interest dreamed up so the film-makers could have a love interest.

She’s often sharply written, always shrewdly performed by Hathaway, and there’s certainly more going on with this character than with most big-screen lovers.

Her appearance feels like a forced entry into the story, though, as newbie salesman Jamie meets her at a doctor’s office, where she’s come to get fresh prescriptions for all the drugs she needs to fight early onset Parkinson’s disease.

Jamie’s a ladies’ man whose love life prospers on the road. Maggie’s similarly interested in casual sex at most, partly because of her illness, partly because of sour past relationships.

Neither wants anything deep or long-term, and both seem fine parting after a one-night stand. And then, somehow, they’re in a relationship, quickly and clunkily crafted by the film-makers so they can proceed to stage two, the bumpy road to love when disease is involved.

Yes, it’s different, but it plays out as superficially and inevitably as if either Jamie or Maggie had a possessively overbearing mother, or a bratty kid from a previous relationship, or any other oversimplified obstacle to romance.

Zwick — back in the interpersonal mode of his 1986 feature debut About Last Night after epic dramas and action tales such as The Last Samurai and Blood Diamond — delivers a fresh scenario but a stale pay-off.

Along the way, we get entertaining side glimpses into the cut-throat world of pharmaceuticals as Jamie partners up with a veteran salesman (Oliver Platt) and tries to woo a key doctor (Hank Azaria) in his territory to prescribe his company’s drugs over a competitor’s.

A little less of the predictable love and more attention to these other drugs might have given the movie a rosier glow.