Typically, vitamin C needs to be used at a low pH to be effective, whereas niacinamide works better at a higher / neutral pH level. Vitamin C inhibits tyrosinase, the enzyme responsible for melanin production that gives our skin pigment, while niacinamide blocks the pigment from transferring within our skin cells. Combining these two ingredients often delivers better results than simply using one or the other.
Carrot & Stick, Formulyst, SkinCeuticals, The Ordinary, Mad Hippie, and Obagi are a few brands we’ve reviewed that offer effective vitamin C serums.