If you thought of this, you get a gold star.
It's true that the most effective forms of retinol and vitamin C are EXTREMELY sensitive to light and air (and, no, there aren't "stabilized" forms of these, contrary to what many brands claim––ferulic acid just mildly extends the life of ascorbic acid before it turns brown and sour). Luckily, your skin absorbs these ingredients in their pure form faster than they degrade if properly applied to a damp, freshly cleansed face! Our serums are formulated specifically to optimize absorption even further. That said, your skin does do its best absorption in the dark. So might as well stay out of direct sunlight for 30 minutes after you apply any quality ingredient.