Serums are fast-absorbing skincare products designed to deliver a high concentration of active ingredients to the skin. They are typically used after cleansing and before moisturizing as part of a skincare routine. Common types of facial serums are Hydrating Serums, Anti-Aging Serums, Brightening Serums, Acne-Fighting Serums, Soothing Serums, Antioxidant Serums, Exfoliating Serums.