This powerful dual-phase vitamin serum activa tes when combined to leave skin looking younger and brighter. Skin is re-energized with a surge of vitamins A, C and E, and is protected against the effects of seasonal changes and environmental hazards that can lead to visible signs of aging.How to use: Apply morning and evening to clean sed skin. Mix 3-5 drops from each vial in the palm of your hand, then use fingertips to apply to skin in upward and outward motions. For optimal results, use before Flawless Skin Moisturizer. Style Name: Laura Mercier 'Flawless Skin' Multi-Vitamin Serum. Style Number: 346549.