‘True Blood’ star Joe Manganiello is unrecognizable in vintage photo

He may transform into a werewolf in "True Blood," but Joe Manganiello's biggest transformation occurred in real life.

A recently released vintage photo shows the 36-year-old hunk as a scrawny, bespectacled teenager with a pretty bad haircut. Manganiello shared the photo while promoting his new book, "Evolution: The Cutting Edge Guide to Breaking Down Mental Walls and Building the Body You've Always Wanted," on HuffPostLive on Tuesday.

"Look at that before picture," Manganiello said. "If I can transform from that skinny kid, who couldn't do one pull up, into the guy who's on the cover, anybody can do it."

Despite having been captain of a number of his school sports teams, Manganiello said that he didn't feel like much of a winner as a teen.

"You hear about these soccer games kids play when goals aren't counted. Everybody gets the orange slice and the pat on the back and everybody says 'Good job!'" he said. "And that wasn't the case for me and I think I benefited from that."

But the actor isn't bitter about not measuring up to the likes of Arnold Schwarzenegger.

"I'm glad that I lost, I'm glad that I failed, I'm glad that I felt that way and decided to do something about it," Manganiello told the Huffington Post. "The embarrassment of that, I never wanted to feel that way again and it drove me."

Manganiello's book includes trainer Ron Matthews's fitness regimen, which the actor followed to get ready for his first shirtless scene in "True Blood" years ago.

"It was a very transformative six weeks," Manganiello said of the workout.

During the interview, he also discussed being sober for 11 years, having realized drinking had gotten in the way of his life. "There was a period of about four years where I needed to quit drinking," he said. "My life was ruined. I was homeless, careless and broke with no career."

Now that's what we call an evolution!