This breakthrough vitamin C serum for oily and blemish-prone skin combines 0.5% silymarin, or milk thistle extract, 15% L-ascorbic acid and 0.5% salicylic acid to help prevent oil oxidation that can lead to breakouts and visible signs of aging. Oil-free and clinically tested, this oil-reducing vitamin C serum improves skin texture, skin clarity and fine lines while minimizing the look of pores and other visible aging signs.