Kiehl's Dermatologist Solutions Retinol Skin-Renewing Daily Micro-Dose Serum, with a Precise, Daily-Strength Concentration of Pure Retinol, Peptide & Ceramides. Clinically tested to steadily promote cell turnover and visibly improve firmness, reduce wrinkles and refine texture while minimizing discomforting effects including redness, dryness and peeling. This efficacious serum, with Pure Retinol, uses precise ratios of potent ingredients to steadily promote cell turnover, visibly improve firmness, reduce the appearance of wrinkles and refine skin texture. With each pump, this daily-strength concentration helps bring fresh new cells to the surface to renew the look and feel of skin. Combined with Peptide and Ceramides, this formula fortifies the skin barrier to help minimize discomforting effects including visible redness, dryness and peeling. Skin is visibly smoother and firmer for a more youthful-looking appearance.