Retinol Serum 2 is a concentrated serum containing very high levels of vitamin A. Retinol promotes healthy glowing skin by normalising the appearance of skin imperfections and sun-damage. People whose skin has already adapted should use Vita-Antioxidant AVST Moisturizer C-Quence 3 daily and always in the correct order, starting with Retinol 1, then 2 and finally 3.