Austin Butler is stripping it down — chiseled, shirtless, and smoldering for a brooding magazine shoot … while revealing the punishing breakdowns that nearly broke him before this glow-up.

Feast your eyes on these hunky shots — the actor flexes hard on the cover of Men’s Health, flashing a body carved like marble and proving he’s in peak condition.

The pics speak for themselves — Butler’s looking damn good. But he admits in the interview, he dragged his body through extremes — from pounding doughnuts and drinking ice cream for ‘Elvis’ … to punishing workouts and restrictive dieting for “Dune: Part Two.”

But it wasn’t until training for Darren Aronofsky’s upcoming flick “Caught Stealing” that Butler really hit his stride — dialing in on what actually works for his body.