Madonna has joined Instagram.

The 'Girl Gone Wild' singer followed in the footsteps fellow celebrities such as Rihanna and Beyonce by joining the growing photo-sharing social networking site yesterday (10.02.13), and she instantly caused waves by posting a picture of her cleavage.

The 54-year-old star toasted her arrival on the social networking site with a photo of her sipping a dirty martini and captioned the shot declaring: ''Cheers motherf**kers! I'm on instagram (sic)''

Madonna later sent out a suggestive post-workout snap, holding her camera up to her chest and exclaimed that she was ''addicted to sweat''.

The saucy cleavage-baring picture attracted over 8,000 likes from fans, with one commenting: '' Boobs rules! LUV @madonna #fit#madonna (sic)''

Since joining Instagram yesterday, the 'Hung Up' hitmaker has already attracted more than 56,000 followers.

Madonna's account on the photo sharing website marks her first foray into social media since briefly launching a Twitter account in March 2012 to promote her album 'MDNA', but the profile has since become inactive.

The singer has previously courted controversy on her 'MDNA' world tour, exposing her right breast during a concert in Istanbul, Turkey while performing her hit song 'Human Nature' in June 2012.