The rise of ‘sexiest ever’ Doctor Who assistant Karen Gillan from former party animal to Hollywood A-lister

IT is a regeneration as startling as any that a Time Lord could muster.

Former party animal and “sexiest ever” Doctor Who companion Karen Gillan has put her wild ways aside to become a serious, bona fide Hollywood star.

The transformation has made her the most successful Tardis traveller ever.

Her latest movie, Guardians Of The Galaxy 2, has made more than £80million in just three days of its limited release.

And when it opens in the US on Friday, pundits are confident it will top the box office and become one of the year’s biggest earners — which will turn Inverness-born Karen into a genuine Los Angeles A-lister.

It is an astonishing feat for a 29-year-old who was known for her chaotic partying while playing Amy Pond on the BBC1 show, which she joined in 2010.

Back then, she was often snapped slumped in the back of taxis or tumbling out of trendy London nightspots like The Box.

On a trip to New York in 2011, after a night of partying with co-stars including then-Doctor Matt Smith, she was famously found naked and mumbling at 7am in the corridor of a New York hotel.

It was, perhaps, the final embarrassment.

A few months afterwards, Karen announced she would be leaving the top-rated show the following year.

In 2013 the Scot, who had been rumoured to have dated Matt, 34, quietly moved to Los Angeles.

There, the healthy-living ethos — together with her own determination — has catapulted her into the movie big league, playing cut-throat space pirate Nebula in the Marvel movie franchise.

An insider said: “Karen used to be quite a party-girl back in London.

But in LA she has had a rethink and stayed well clear of that scene.

“Instead she has a tight-knit group of well-connected friends and spends her time buried in scripts or swotting up on indie and classic movies.”

“Her strategy has paid off.

“Karen has this bubbly, ditzy image in public which hides her inner toughness and ambition.

“After all, you don’t go from being a relative unknown in America to headlining a blockbuster superhero movie without having a hell of a lot of drive — and a plan.”

A recent early-morning tweet pointed to her dedication.

She wrote: “Got my coffee and it’s Saturday! Ready to read some scripts!!”

Having initially mocked Californian fads like wheatgrass shots, Karen is now a firm convert to juicing.

Her gym-honed 5ft 11in figure is thanks to fashionable “SoulCycle” spinning sessions at her local gym.

Karen, whose Scottish burr now bears an American twang, said of her new lifestyle: “It’s funny — some British people get angry because I’m not out drinking and I’m being really proactive with my downtime.

“They’re like, ‘What have you become?’. But I’m like, ‘How is this a bad thing?’.”

In America, she has regained the sort of ambition that saw her take acting classes seven days a week while at secondary school.

She recalled: “I dreamed of being an actor every night.