Ingredient Encyclopedia

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Discover what’s inside your skincare — from retinol to aloe vera — with clear guides on benefits, uses, and safety.

Ingredient Encyclopedia

Tetrahexyldecyl Ascorbate – Benefits, Side Effects & Uses

by ThankMeNow Editors on Sep 10, 2025
Tetrahexyldecyl Ascorbate (THD Ascorbate) is an oil-soluble, stable precursor of Vitamin C ($C_{50}H_{92}O_7$). In the hierarchy of Vitamin C, it is often called the "Deep-Diving Derivative." Unlike water-soluble L-Ascorbic Acid, which often struggles to get past the skin’s natural lipid barrier, THD Ascorbate’s fatty structure allows it to integrate seamlessly into the skin’s oily layers. Once inside, skin enzymes convert it into active Vitamin C. This unique delivery method makes it up to 4x more effective at penetrating the skin than traditional Vitamin C, while maintaining a neutral pH that significantly reduces the risk of surface irritation or "stinging."