Form of vitamin C combined with glucose. It can function as an antioxidant, but only minimal research substantiates this activity, and its antioxidant potential is weaker than that of ascorbic acid. The research that does exist for its skin-brightening potential involved a combination of ascorbyl glucoside with niacinamide, but it is possible the benefit resulted from only the niacinamide, and not the combination.
References for this information:
Journal of Photochemistry and Photobiology, July 2012, volume 112, pages 7-15
Skin Research and Technology, May 2006, issue 2, pages 105-113