Justin Timberlake's not the only guy who's had to drop trou for Madonna .

At a press conference Thursday for Guy Ritchie's new action flick RocknRolla, actor Gerard Butler revealed: "I got in a B-12 shot in my a-- by..."

"My wife!" Ritchie interrupted.

See photos of Madonna's past and present loves.

"Yeah, I got a shot from his wife Madonna!" said Butler. "I was sick, and she was a nurse basically.

"Guy introduced me to her and she said, 'You're the sick one?' and I said, 'Yes,'" Butler recalled.

"Well, she was amazing. She just said, 'Drop your pants,'" Butler added. "I stood there with my little bottom out, and she gave me a shot in the bum!"

While some claim the shots help in the production of red blood cells and boosting energy, others like Dr. Michael Karp of the University of Southern California tell Us, "there's not a lot of science behind that."

And Butler would agree.

"It didn't work at all — I got more sick!" the actor said. "But I appreciated the effort."

http://www.usmagazine.com/Gerard-Butler-Madonna-Told-Me-to-Drop-My-Pants