Ascorbic acid, the pure form of vitamin C, is one of the most effective skincare ingredients we have. There are lots of vitamin C derivatives on the market, such as sodium ascorbyl phosphate (SAP), magnesium ascorbyl phosphate (MAP), and ascorbyl palmitate. These derivatives are used primarily because they’re more stable and easier to formulate with than pure ascorbic acid. However, these derivatives are also much less effective than ascorbic acid; for example, one study showed that SAP doesn’t even penetrate the epidermis.
Enter ascorbyl tetraisopalmitate (ATIP), a stable yet highly effective derivative of ascorbic acid. Unlike other derivatives, ATIP is oil-soluble. The skin’s outermost barrier is oil-based, so other oil-based ingredients are generally able to penetrate much better than water-soluble ones. That’s definitely the case with ATIP, which has been observed to penetrate both the epidermis and the dermis below it.
Once ATIP is in the skin, your body converts it to ascorbic acid, where it does all the phenomenal things that ascorbic acid does for your skin:
-Fights free radicals to mitigate UV damage
-Stimulates collagen production
-Inhibits excess melanin production, fading hyperpigmentation
This article is updated & reviewed by Alli Reed, PhD on 4/20/2023.