Zac Efron's latest body transformation has really got the star's fans going on social media.
The 33-year-old actor took part in the Earth Day! The Musical, which has just aired on Facebook.
Bill Nye teamed up with Justin Bieber to bring awareness to climate change, but it wasn't just their bid to help save the planet which got everyone talking.
Zac seems to have a more squared out jawline in the video, and his legion of fans were quick to notice.
Not only that, but the Hollywood heartthrob appears to have even more muscle than before.
The internet was awash with comments and his new look left fans a bit confused.
© FacebookThe actor's jaw has really got people talking
"I refuse to believe this is Zac Efron," one wrote.
"I woke up and zac efron got botched w*f im so devastated," another said.
An emotional third fan wrote: "I just found out about this and I am literally crying, there are actual tears coming out of my eyes please tell me it's all just a nightmare please zac efron has been the my whole life."
There is absolutely no suggestion that Zac has gone under the knife but some fans did set off plastic surgery rumours.
© Getty Images for Tribeca Film FestivalHis appearance has really changed over the past few years
Another joked: "Zac efron disappeared and they tried to replace him but didn't have the budget."
But many fans loved his new look.
One wrote: "People should leave him along he still looks gorgeous."
Another jumped to his defence, writing: "He still looks DAMN good!"
It comes after he split with his girlfriend over her possible casting in a controversial new show, reports claim.
He made headlines when he was linked to stunning Vanessa Valladares last year, but reports emerged that they'd called it quits after a 10-month romance.
On Thursday it was claimed that Vanessa's potential casting in Byron Baes, a new reality show that has sparked the ire of local residents, was partly behind their "split."
© REUTERSLong gone are the floppy-haired Disney days
"He's a very good person who wanted a genuine, normal, down-to-earth partner," a source told Daily Mail Australia.
"Zac sent her home from the set [Down to Earth with Zac Efron] last week. There still may have been a chance.
"I'm sure the final nail in the coffin was him seeing the story of her being possibly on Byron Baes and the claims that he was helping her get on it."