Robert Downey Jr has revealed that drugs and alcohol are not the only addictions he's battled in the past – he used to abuse his penis too.

The actor – who has been married to movie producer Susan Levin since 2005 – admits that he used to be a “compulsive masturbator.”

"I was a compulsive, serial masturbator,’ he tells The Sunday Times.

"But it was the best thing I could have been. I utilised that organ and rode it for everything it was worth."

Luckily for RDJ and film fans, he has since outgrown the habit.

But he still reckons all men are driven by sex.

"It’s no longer a motivating factor for me. My union with Susan is sacred," he says.

"Almost always, guys want to get laid. They have a girlfriend, they want to f*** her friend. But I’m not that guy."