Serums are a skin care product with high concentrations of certain active ingredients. These ingredients can be things like hyaluronic acid (to reduce the appearance of lines and wrinkles), vitamin C (to brighten the skin and help reduce the appearance of pigmentation and age spots). One may ask what the difference between a moisturizer and a serum is; Moisturizers are formulated to keep the skin hydrated by putting a protective barrier between it and the outside. Serums are formulated to penetrate deeply into the skin to deliver key ingredients. The molecules in a serum are smaller than those in a moisturizer. This means it can deposit ingredien ts deeper into the skin. Gia Skin Care serums are truly magnificent and deliver nutrients to all skin types. The difference can be quite remarkable, provided you use the serum correctly and consistently. Serums are applied after cleansing and toning, but before your moisturizer. Ideally, apply the serum while your skin is still slightly damp from cleansing. As with cleansing and moisturizing, don’t forget to include your neck and upper chest when applying the serum.