The actor made the statement after joining the social networking site and acquiring over 2.7 million likes in a few days.
Khan revealed via a video message on his page: "A lot of people told me 'There are so many of your fake Facebook pages, so when are you joining it?' So here I am on this platform.
"So all the fake pages either just join this page or, what can I say? Fake off."
Khan is the latest Bollywood star to set up an official page, after Amitabh Bachchan launched an account last month.
The action star also confirmed that his charitable clothing range will soon be available for retail across India.
"We are opening Being Human stores all over India starting October," he said.
Watch the trailer for Khan's current release Ek Tha Tiger below: