The solid theory that explains Johnny Depp's dramatic weight loss.

When photos were posted of actor Johnny Depp with fans at the Four Seasons hotel in St Petersburg, Russia, people could barely believe their eyes.

The 54-year-old seemed to have lost a considerable amount of weight and was looking noticeably gaunt.

Some fans began to worry that the Pirates of the Carribean and Fantastic Beasts star was under stress, or possibly ill.

Depp is currently on a tour with his rock tribute band the Hollywood Vampires.

A post shared by SoniaDelFaces (Facesonthebox) (@soniadelfaces) on Jun 3, 2018 at 8:38am PDT

“Is he good health wise?” commented one fan.

“It’s either stress or he real sick. I’m praying it’s for a movie,” said another.

I hope Johnny Depp is okay, just saw photos of him in Germany and honestly wouldn’t have realised it’s him if it hadn’t of said his name he looks really ill

— Megan (@MeganJadeM) June 3, 2018

However, eagle-eyed fans have a plausible, and more hopeful, explanation behind Depp’s transformation. And the evidence can be found on his IMDb page.

The actor is starring in an upcoming film called Richard Says Goodbye, in which Depp plays the protagonist, a college professor who is diagnosed with a terminal illness.

“He has a new role where he has cancer,” wrote a clued-in fan on an Instagram post.

“It’s really for a movie. He playing a terminally ill person.. he even shaved his eyebrows,” wrote another.

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Despite this, others are blaming the initial photos for being misleading. One Twitter user said that having just seen him in concert, Depp didn’t look “thin” in person.

Just saw #JohnnyDepp in concert in Hamburg. He looks healthy, happy and he had so much fun. He didn’t look sick, pale or thin at all. How pictures can deceive an impression..

— Swiggity Swag (@its_batcountry) June 2, 2018

People agreed.

I met him 2 weeks ago at Foxwoods and he was in absolute perfect health! Happy, smiling, and his hug was fantastic! He’s in great shape!

— 4 the ???? of Depp ???? (@JdeppLove) June 2, 2018

Also when your head is shaved on the sides it can make you look thinner.
Depp has always been more on the thin side his whole life.
I have seen other pics in the same time frame and he looks fine. He was just probably tired in that one shot of him.

— Donna Faye Palumbo (@palumbo_faye) June 2, 2018

And God forbid you’re tired sometimes. ‘Cause you’re flying around the world no less, how dare you!

— Swiggity Swag (@its_batcountry) June 3, 2018