Stable form of vitamin C that is considered an analogue of L-ascorbic acid. Unlike pure vitamin C (ascorbic acid), tetrahexyldecyl ascorbate is lipid (fat) soluble. Some researchers believe this form of vitamin C has a greater affinity for skin because its fatty acid component helps aid penetration and protect the vitamin C component from rapid oxidation. This form of vitamin C has been shown to stimulate healthy collagen production and reduce wrinkle depth. 
- Fitzpatrick R, Rostan E. Double-Blind; Half-Face Study Comparing Topical Vitamin C and Vehicle for Rejuvenation of Photodamage. Dermatol Surg. 2002;28(3):231-6.