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 involved a combination of ascorbyl glucoside with niacinamide, but it is possible the benefit resulted from only the niacinamide, and not the combination. 
- Tsai F, Wang Y, Chen C, Hsieh C, Cheng Z, Wu Y. Evaluation of the antioxidative capability of commonly used antioxidants in dermocosmetics by in vivo detection of protein carbonylation in human stratum corneum.. J Photochem Photobiol B. 2012;112:7-15.
- Hakozaki T, Takiwaki H, Miyamoto K. Ultrasound enhanced skin-lightening effect of vitamin C and niacinamide.. Skin Res Technol.. 2006;12(2):105-13.