Bradley Cooper on 'Limitless:' 'It's About Power'

Rogue Pictures

He admits he's "nervous" about carrying the film -- and lobbied hard to work with Robert De Niro, "the reason I became an actor'."

Bradley Cooper's Limitless hits theaters this Friday.

The actor admits he's apprehensive about starring in the Neil Burger-directed thriller, in which he takes a drug NZT to access 100 percent of his brain, and then deals with the fallout.

"A nervous laugh, that's OK," he tells the Sydney Morning Herald of his departure from comedies, such as the Hangover. REVIEW: Limitless

But he's eager to explore "big storytelling opportunities'."

"I mean, three years ago, I just wanted to get a job,'' he told Metro New York at a junket for the film. "When The Hangover came out it got a little easier, although I still audition for stuff."

''If you just take what comes along, at some point you're going to be in serious trouble because what comes along is probably stuff people have seen you do before," he went on.

Cooper was added to the cast of Limitless, adapted from Alan Glynn's novel The Dark Fields and penned by Leslie Dixon, when Shia LaBeouf pulled out following a car accident injury. VIDEO: Limitless' viral success

He then lobbied to have Robert De Niro -- whom he calls "the reason I became an actor" -- to appear in the film. De Niro tells the Sydney Morning Herald that playing corporate king Carl Van Loon wasn't his most challenging career moment, "but I put a lot of work in it."

''I wanted to work with Bradley and Neil,'' De Niro says. ''Sometimes, even when it's not perfect, you do it to work with people so you can work with them again later on. You establish a relationship.''

Next stop for Cooper: directing.

''If this is successful, maybe I'll do one or two more of these and then I would want to direct. I love the entertainment business," he says. "I've met the greatest people in the world. People who are very successful, like Bob [De Niro] and Liam Neeson and Christopher Walken: these are wonderful guys.''