Uniquely formulated to stabilise powerhouse ingredients Vitamin C + Retinol, Kate's power serum visibly brightens, firms and evens tone while working to improve skin texture, smooth lines and neutralise free radicals that can cause premature ageing. How to use At night, apply a thin, even layer to face and neck, avoiding the eye area. Follow with your favorite Kate Somerville moisturiser. While using this product, also use a daily sunscreen.