To date Bradley Cooper’s most popular role has been in the runaway hit comedy The Hangover, where he and his reprobate friends were intent on destroying a few brain cells through the somewhat reckless combination of pills and alcohol.

In Limitless he is once again hurling back pills with abandon – only this time it has the opposite effect.

Thanks to a new wonder drug, NZT, he can suddenly use his mind to its maximum potential, transforming him from time-wasting blocked writer to smartest man in the room. Any room.

“If people come out of the movie saying they wouldn’t take the drug they are lying,” laughs Bradley.

‘‘It is a great hook. What would you do if you could unlock your full potential and you could be the best version of yourself?”

His character, Eddie Morra, becomes the closest thing you can get to a superhero without the benefit of a cape or tights.

“If I can figure out what everyone is thinking, what everyone wants and know how to talk to each one of them individually to get what I want from them, that is a very powerful position I am in,” he agrees.

“That is where he is. There is no level playing field. There is the playing field and there is Eddie.”

Unlike conventional superhero movies there is enough ambiguity about the character that we cannot be certain he will use his “powers” for good or evil.

“Eddie is complicated but I don’t think he has this Megamind mentality. He doesn’t want to steal the moon.”

The film marks another step up for 36-year-old Bradley. He started out in supporting roles (in Alias) – as the best friend of the girl rather than the dashing CIA agent who gets the girl, or the arrogant, overly competitive boyfriend who loses the girl to the louche leading man (The Wedding Crashers).

The success of The Hangover propelled Bradley and his co-stars a little closer to the A list, and in Bradley’s case onto The A-Team – as the smooth talking con-artist Face in last year’s big screen remake of the 80s cult show.

“It is hard to say if it was a vertical shift but it was a shift,” he says. “Certainly it was vertical financially.