Hollywood hunk Bradley Cooper has stepped up to leading man status with his role as a struggling writer in thriller Limitless, released in cinemas on Wednesday, March 23. The actor talks about the film's unique premise of a drug that makes you superhuman, dealing with his new-found fame and 'stalking' Robert De Niro.

By Kate Whiting.

With his chiselled good looks, intelligence and cracking sense of humour, Bradley Cooper seems to have it all.

His easy-going charisma makes both women want to be with him and men crave a pint in his company.

But despite his charms, Cooper has still taken more than 10 years to secure his first bona fide leading man role.

He owes this honour in part to a certain cult comedy called The Hangover, which took him and co-stars Ed Helms and Zach Galifianakis from virtual unknowns outside the US to global movie heroes when it was released in 2009.

The film-makers behind his first solo outing, Limitless, decided to take a punt after seeing how the buddy movie performed.

"He's an excellent actor, but studios always ask film-makers if they can finance the movie on an actor's name," explains Limitless director Neil Burger. "Luckily The Hangover came out while we were casting and suddenly he was a real possibility."

The buzz around Cooper is about to get really loud, with The Hangover Part II hitting screens in May, but he's not letting it go to his head. If anything, he's got a very keen sense of the vagaries of Hollywood.

"There is a scenario in which Limitless doesn't do well, Hangover Part II is a huge success and it's like, 'You can make buddy comedies the rest of your career'. Everything is tricky," he says, looking slick in a steel grey shirt and manly cardigan, his fluffy brown locks tamed.

"If it's not well received, it may be tougher for me to have a studio or someone funding the movie say, 'We can rest the main character on this actor's shoulders and feel he can be compelling enough to watch for two-plus hours'."

Cooper is compelling though. Limitless sees him play Eddie Morra, a New York writer who's down on his luck. He's got chronic writer's block, his flat's a mess, the hair's out of control and his girlfriend (Abbie Cornish) is not impressed.

So when he's offered a smart drug that will unlock his full brain capacity and allow him to become the perfect version of himself, he willingly swallows it.

"The script jumped off the page - when I read it, I couldn't believe that this movie wasn't even made and if it's not, then how come I'm even having an audition for it?" he says, still incredulous he landed the part.

The pill, called NZT, allows Eddie to recall everything he's ever seen, read, or heard and makes him super-efficient. He knocks off his novel in four days, picks up languages with ease, then starts to plot what else he can achieve.

It's not long before he's wowed Wall Street by earning millions on the markets and impressed mega-mogul Carl Van Loon, played by Robert De Niro. But the drug has powerful side-effects and attracts some unsavoury characters who want to get their hands on it.

Working with screen icon De Niro was something of a dream come true for 36-year-old Cooper, who grew up watching him on screen.

"My connection to De Niro predates the movie - at least in my mind," he says, laughing, aware he sounds like a stalker. "Before I met him, I thought, 'God his hands are just like my grandfather's' and I didn't even know he was Irish and Italian, like my family.

"He was one of the first actors who made me cry when I watched him."

When Cooper was studying at the Actors Studio Drama School in New York back in 1998, De Niro came for a question and answer session and an awestruck Cooper plucked up the courage to ask him a question.

"I was so embarrassed, I stayed standing up a beat too long, even when the next person was asking their question," he says, grinning at the memory.

Fast forward 10 years and, after auditioning unsuccessfully to play De Niro's son in another movie, Cooper was asking his idol to play a character in his own film.

"It was a very odd turn of events," he says, taking a sip of green tea, noting that he can now call 'Bob' a friend.

Cooper's career began not long after that Q&A session, with a small part in Sex And The City. He went on to star in TV shows Nip/Tuck, Alias and Law & Order and had his first big movie role as Rachel McAdams' other half and Owen Wilson's nemesis in 2005's Wedding Crashers.

But when The Hangover premiered in London some four years later, he and his co--stars still weren't very well known.

"We actually thought they'd wrangled people to line the red carpet," he admits.

However, the film about three guys dealing with the aftermath of a Las Vegas bachelor party won fans all over the world and even picked up a Golden Globe award, propelling its stars into the stratosphere.

"It was certainly a vertical shift financially," says Cooper, who reprises his role as Phil Wenneck in Part II. "I never thought I would get paid as much money as I have been for Hangover Part II in my whole life, it was insane!"

Cooper was then cast as Lt 'Faceman' Peck in last year's remake of The A-Team, which helped to cement his big box office status.

After Mike Tyson cameo-ed in The Hangover, rumours have been rife that Cooper's A-Team co-star Liam Neeson is appearing in the sequel. But he's steering clear of gossip.

He will, however, talk about the teaser trailer. "Todd [Phillips, the director] emailed it to me and said, 'What do you think man?' and I was like, 'Jesus'. We're in Bangkok, Zach's head's shaved, Stu's got Mike Tyson's tattoo on his face, there's a drug-dealing monkey, you're thinking, 'What the heck?'

"It's so insane, but we played it real and I think that's why the first one was so palatable. As a viewer, you believe it. Yes there's a Chinese man's testicles on Phil's neck, a tiger in the bathroom and Mike Tyson singing In The Air Tonight, but I believe it."

As any successful actor will attest, fame does come at a price. "My father just passed away, so now my mother lives with me and she has to deal with the paparazzi, which bothers me because she didn't ask for it.

"For the most part, they're OK, but at the airport the other day, we were waiting for a cab with all this luggage and we were ambushed.

"I just felt that thing in the back of my head go, 'Ah, I want to hit this guy because he's not stopping' which is the worst thing you can do because that's all they want.

"Show any sign of aggression and they think they've got a live one and then they're going to be all over it, so it's such a process of constant restraint."

Luckily Cooper's got his macho side under control. He saves that for the cameras.

Extra time - Bradley Cooper :: Bradley Cooper was born in Philadelphia on January 5, 1975.

:: He reportedly took out a loan of £44,000 to pay for acting school in New York.

:: He was married to actress Jennifer Esposito for four months and has been linked to Jennifer Aniston. He's now rumoured to be dating Renee Zellweger after they met on the set of thriller Case 39.

:: The worst rumour he's ever read about himself was that he had taken his dogs to a canine spa. "That wouldn't have made me angry except it was the same day that one of my dogs had died - it's amazing what people make up," he says.

:: Limitless is released in cinemas on Wednesday March 23.