Ascorbyl Tetraisopalmitate (Vitamin C Ester)

A lipid-soluble ester of vitamin C — ascorbic acid bound to four fatty-acid chains.

How it works

Where classic L-ascorbic acid is water-soluble, acidic and unstable, this ester is oil-compatible and stable at skin-friendly pH. Skin enzymes gradually release ascorbic acid after absorption. Research associates it with the antioxidant and tone-evening effects of vitamin C with substantially less of the stinging that concentrated L-ascorbic acid can cause.

Where it fits

Its gentleness makes it the vitamin C form usually chosen for sensitive skin, and its oil-solubility suits creamier serum textures.

Pregnancy and breastfeeding

Vitamin C derivatives carry no established topical concerns and are conventionally considered suitable.