SUNDAY RILEY C.E.O. 15% Vitamin C Brightening Serum tackles dullness head-on. Infused with a potent 15% vitamin C, this serum visibly diminishes dark spots and discolorations. The advanced formula encourages firmer, plumper skin, helping to restore youthful bounce and even tone. It uses THD Ascorbate, an ultra-powerful form of vitamin C. This oil-soluble solution absorbs rapidly into the skin, unveiling visible anti-aging benefits.