Cetaphil Vitamin C Serum 30ml is a brightening face serum built for the people pure vitamin C usually burns: sensitive skin. Its vitamin C is 3-O-ethyl ascorbic acid, a stable, no-sting form, backed by niacinamide in third position and a brightening peptide most labels never mention. The 30ml formula fades dark spots and dullness over weeks while three plant sugars and glycerin handle a 24-hour hydration claim. It is fragrance-free, paraben-free, and tested by the brand on sensitive skin. One honest note: part of the instant glow comes from light-reflecting particles that rinse off; the real spot-fading is the slow work of the actives.