Bottled in an entirely oxygen-free environment means all the ingredients in Protocol’s Vitamin C Superserum remain protected and preserved, which is crucial in keeping them powerful and potent—especially when vitamin C is involved. Futher, the bottles themselves are clinical-grade and don’t let any air in as you use them, so the serum stays fresh and functional. Along with natural oils and fruit extracts, the therapeutic active (designed to penetrate both layers of skin for longterm results) is the 10% L-ascorbic acid, pH 3.46 in this potion. Once applied, it’s quickly absorbed, with a slightly cooling sensation. Ultimately, the Superserum should help skin become smoother and brighter. We find it to be very refreshing and restorative after a day in the sun.