In most versions of J. M. Barrie's 1904 play Peter Pan, fairy dust is the magical element that allows the protagonists to fly. Provided by the diminutive fairy Tinker Bell, it's what helps the children get to Neverland. However, the magical powder wasn't always a part of the story. In fact, fairy dust was added later for health and safety reasons. Originally Peter and the Lost Boys could fly unaided, but after several reports of children injuring themselves attempting to fly from their beds, J.M. Barrie added it as a necessary factor for flying.

Source: The Guardian