In the ineffectual new fantasy-thriller “Self/less” the fantastical plot device — a body-switching process costing millions and not covered by any known health plan — is called “shedding.” You buy yourself a new, longer life in a younger person’s body, and your troubles are over. Or ARE THEY?

Ben Kingsley, sounding like a compendium of every attempt at a New York accent ever heard in the movies, plays Damian Hale, a Trump-like Manhattan developer (i.e., he’s a selfish bastard) who beats a terminal cancer prognosis by hooking up with a mysterious biogenic company run by purring, movie-stealing Matthew Goode. Early on in “Self/less” Hale gets zwooped into the body of a new human vessel, portrayed by top-billed Ryan Reynolds.

The intrigue in “Self/less,” only occasionally intriguing, comes with the complications. When Kingsley’s character turns into Reynolds, his memories are no longer strictly his own. In his addled mind’s eye the new Hale experiences flashes of another life, a different past. It’s up to this new, strapping version of Hale to figure out what shedding entails, and learn the identity of the woman (Natalie Martinez) he can’t get out of his head.

Most of “Self/less” takes place in New Orleans, which has two advantages to a modestly budgeted project such as this one. One: It’s a place that reeks of death and rebirth, photogenically. And two: Louisiana’s one of the cheapest places you can make a movie. The producers of “Self/less” scored a solid success with the inventive, cleverly elaborated “Looper.” It’s possible director Tarsem Singh’s film will receive a similarly warm welcome. But I doubt it.

Singh’s previous work includes “The Cell” (Jennifer Lopez in a series of swanky nightmare scenarios) and “The Fall,” a strange, grandiose, somewhat icky adventure story set in the silent film era. “Self/less” is much smaller, and not nearly strange or transporting enough. Small can be good in speculative fiction; look at “Ex Machina,” for example. This script by Alex Pastor and David Pastor reveals its secrets predictably, and Singh struggles to make his locations come alive on screen.

Reynolds can be charming and effective as a leading man in both comedy and drama, but his somewhat glazed expression and tweezed good looks can work against him. The cast, including ever-reliable Victor Garber as Hale’s longtime friend and colleague, does what it can. “Self/less” hews closely enough to the premise of the 1966 John Frankenheimer thriller “Seconds” to qualify as an unofficial remake. Then again, anyone who remembers that one is not in the target audience for this one.