SkinCeuticals C E Ferulic. 1 × SkinCeuticals C E Ferulic Serum. Its advanced antioxidant blend features15% L-Ascorbic Acid (Vitamin C) ,1% Alpha Tocopherol (Vitamin E), and0.5% Ferulic Acid, working together to help improve the appearance of fine lines, uneven skin tone, loss of firmness, and visible signs of aging.