media_removed_toofab 2013

Actors who drastically change their weight for roles can appear shocking, but new pics of Matthew McConaughey have our jaws on the floor.

The actor -- who was just seen as ripped stripper boss Dallas in "Magic Mike" -- was spotted in New York on Monday, looking scary thin in preparation for his next movie, "The Dallas Buyer's Club."

The 42-year-old is set to play Ron Woodruff, a real-life cowboy who contracted HIV through drug use in the '80s and was then forced to smuggle life-saving drugs across the Mexican border.

Matthew recently explained the weight loss on Larry King's “Ora” TV web series, “I’m losing some weight. I’ve got a role coming up in the middle of September. I’ve lost about 15 pounds, I’ve gotta lose about 15 more. I should not look healthy by the time I’m doing (filming) this.”

Click "Launch Gallery" above to see more shots of stars who've changed their weight for roles, and watch the video below to see Matthew explain to Larry King what he's doing to shed the pounds.

"The Dallas Buyer's Club" is expected in theaters next year.