AntioxidantOverhyped
Tetrahexyldecyl Ascorbate (TH-Ascorbate)
Also known as: Ascorbyl Tetraisopalmitate, VC-IP
Medically reviewed by ChokChok · Updated April 15, 2026
The prestige-tier stable vitamin C. Penetrates better than L-ascorbic acid, doesn't oxidise, plays well in oil-phase formulas.
What It Does
BrightensAntioxidantStable oil-soluble vitamin CPenetrates deeply
Deep Dive
TH-ascorbate is an oil-soluble ester of vitamin C that's chemically stable, doesn't brown on exposure to air, and penetrates the skin's lipid layers better than water-soluble derivatives. Clinical trials suggest it matches or exceeds L-AA for photoprotection and brightening at equivalent doses. The catch: it's expensive, which is why you'll find it in Sunday Riley Juno, Drunk Elephant C-Firma, and Biossance's rose oil rather than budget formulas.
Best For
DryMature
Pairs Well With
Effective Concentration
0.5–10%. Oil-soluble — penetrates skin's lipid layers effectively.