How often must you use deal with serum? “As frequently as your skin demands it,” explains Sturm, who levels her Hyaluronic Serum 2 times each day, as well as the Super Anti-Ageing Serum and Night Serum On top of that right before bed. A great general guideline is to use https://www.amazon.ca/gp/product/B0D4SG1VQD