Tetrahexyldecyl Ascorbate

Penetrates deeply into the skin through the lipid matrix of the stratum corneum, delivering ascorbic acid directly to viable epidermal and dermal cells. Provides antioxidant protection at the cellular level, neutralizing intracellular reactive oxygen species. Stimulates collagen synthesis from within the dermis by delivering ascorbic acid to fibroblasts more efficiently than water-soluble derivatives. Inhibits melanogenesis through intracellular suppression of tyrosinase, contributing to gradual skin brightening. Offers exceptional stability in formulation, maintaining potency throughout the product shelf life without the discoloration typical of L-ascorbic acid products. Compatible with oil-based formulations, making it ideal for dry or mature skin types seeking vitamin C benefits in a nourishing vehicle.

Apply THDA serums or oils to clean skin in the morning or evening. Because it is oil-soluble, THDA is often formulated in facial oils, oil serums, or anhydrous balms and should be applied after water-based products but before heavier creams or occlusives. In the morning, apply before sunscreen. THDA can be layered with water-soluble actives such as hyaluronic acid and niacinamide without compatibility issues, as it operates in a different phase. Effective concentrations range from 1% to 10%, with some formulations going as high as 20%. Allow the oil to absorb for a few minutes before proceeding with makeup or sunscreen application.

Research published in Biological and Pharmaceutical Bulletin demonstrated that tetrahexyldecyl ascorbate penetrates the skin at significantly higher levels than L-ascorbic acid and magnesium ascorbyl phosphate in ex vivo human skin models, with greater accumulation in both the epidermis and dermis. In vitro studies confirm that THDA is converted to free ascorbic acid by intracellular esterases in human keratinocytes and fibroblasts, with subsequent stimulation of type I collagen mRNA expression. A clinical study found that 10% THDA cream reduced hyperpigmentation scores and improved overall skin luminosity in subjects with melasma after 16 weeks of use, with no adverse events. Stability testing shows that THDA retains over 95% of its potency after 12 months at room temperature in both anhydrous and emulsion formulations, outperforming all water-soluble vitamin C derivatives. Comparative penetration studies using Franz diffusion cells demonstrate approximately 3 to 5 times greater percutaneous absorption for THDA compared to L-ascorbic acid at equivalent concentrations.