Matthew McConaughey says stripping is like "a drug".

The 42-year-old actor was told by director Steven Soderbergh that he didn't have to bare all in new movie 'Magic Mike' - in which he plays former stripper Dallas - but knew he would regret it if he didn't flash his flesh, and was surprised by how much he enjoyed the experience.

He admitted: "It wasn't in the script, but Soderbergh said in the beginning that if it felt right, I could strip at the end of the movie. I said, 'I gotta dance, man.' I would regret it for the rest of my life if I was in a male stripper movie and didn't get up there and strip myself.

"At first it was scary as hell, but then it became like a drug, and I couldn't wait to do it again. Look, I love to dance, but I've never been a stripper.

"Channing [Tatum]'s one of the best hip-hop street dancers I've ever seen, and I didn't want to challenge his style, so I worked on my own strengths. I also knew that my dance had to be the dirtiest. It had to be wonderfully filthy."

Matthew - who stars in the film alongside Channing Tatum and Alex Pettyfer - is known for his toned physique and refused to use a body double in any of his scenes.

Asked if he had considered a body double, he told The Advocate: "No way. That's all me up there. I don't need a stunt ass."

And the actor - who has children Levi, three, and two-year-old Vida with fiancee Camila Alves - admitted all of the cast were in good shape because their "vanity" spurred them on to be as "ripped" as possible.

He added: "Everybody was pretty damn ripped already, but boy, if you really want to get men in great shape, just tell them they're going to play male strippers in a movie and have their s**t onscreen for the rest of time. Vanity, baby."