Every Perricone MD product is based on Dr. Nicholas Perricone's many years of groundbreaking research and innovative patents. This 'Advanced Renewal Infusion Serum' is an intensive anti-aging booster treatment designed to be used in addition to your regular skincare regime. Each of the week-long vials is filled with the brand's H2 Energy ComplexTM formula - when activated, it quickly penetrates the surface layers of the skin for instant results. - Set of four - Works to re-energize and hydrate skin for a visibly brighter and healthier-looking complexion - Diminishes signs of aging like fine lines or wrinkles - Contains firming ingredients to improve the skin's tone and texture -Instructions for use: - Smooth one dropper full on face, neck and décolletage twice daily - Each vial lasts approximately one week, and should be used consecutively for a total of four weeks - 4 x 9ml/ 0.3fl.oz.