Ascorbyl Tetraisopalmitate
Oil-soluble vitamin C derivative. More stable than L-ascorbic acid with better penetration through the lipid barrier. Converts to ascorbic acid inside the skin.
Evidence by route
Topical application
Small clinical studies show brightening and antioxidant effects. Lipophilicity ensures good penetration, but conversion rate to the active form is lower than L-ascorbic acid. No large comparative RCTs.
- Fossa Shirata MM, Maia Campos PMBG. Sunscreens and Cosmetic Formulations Containing Ascorbyl Tetraisopalmitate and Rice Peptides for the Improvement of Skin Photoaging: A Double-blind, Randomized Placebo-controlled Clinical Study. Photochem Photobiol. 2021;97(4):805-815.. PMID 33529350
How to read tiers A–F
- BLimited evidence. One RCT or several controlled studies with limitations
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Sensitive, Dry, Normal, Combination
Combinations with other ingredients
Works well with
Hydroxypinacolone Retinoate
HPR and THD ascorbate are both lipophilic and pH-neutral. Often formulated together in anhydrous anti-aging serums – convenient for retinoid adaptation.
Retinaldehyde
The oil-based THD form of C is oxidation-resistant and pH-neutral. Often sits in a single formula with retinal in anti-aging brands (Medik8, Avene).
Retinol
THD ascorbate is the oil-soluble form of vitamin C and pairs cleanly with retinol and its derivatives in anhydrous and oil-based serums. No pH conflict, no stinging.
About this ingredient
Ascorbyl Tetraisopalmitate (THD ascorbate, Tetrahexyldecyl Ascorbate) is an oil-soluble vitamin C derivative with four isopalmitate chains attached to the ascorbate ring. One of dermo-cosmetics' most respected C derivatives: stable, well-penetrating, and effective at low concentrations. Mechanism. The tetraisopalmitate is hydrophobic and crosses the lipid stratum corneum easily. Inside skin an esterase removes the isopalmitate groups and releases ascorbic acid. Pig skin studies (Ochiai 2006) showed deeper penetration than L-ascorbic acid under matched conditions. In keratinocytes the released ascorbic acid acts as a prolyl hydroxylase cofactor, inhibits tyrosinase, and neutralises free radicals. Where applied. Premium anti-aging serums and creams, pigmentation products, daytime antioxidant formulas. Concentration 2–10%. In Spain in Isdin Isdinceutics Flavo-C Ultraglican, Skinceuticals CE Ferulic (adjunct), Mesoestetic Brightening Foam, Endocare C Ferulic Edafence. Evidence base. Iwai 2014 and Ochiai 2006 showed significant reduction of UV-induced pigmentation and tone improvement with 3% THD ascorbate over 8–12 weeks. Comparison with L-ascorbic 10–15%: THD irritates less, but antioxidant power is comparable in a proper formula combined with vitamin E and ferulic acid. Safety. CIR confirmed safety in 2014. Low irritation risk – better tolerated than L-ascorbic acid, especially in rosacea and sensitive skin. Non-comedogenic, does not photosensitise. Pregnancy and lactation – safe. Topical systemic absorption is minimal; metabolites are ascorbic acid and fatty acid. Particularly suitable for. Sensitive skin, rosacea, post-procedure recovery, patients who do not tolerate the low pH of L-ascorbic acid. A good pick for daytime antioxidant protection under SPF.
Frequently asked questions
Is Ascorbyl Tetraisopalmitate safe during pregnancy?
Ascorbyl Tetraisopalmitate is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Ascorbyl Tetraisopalmitate for?
Ascorbyl Tetraisopalmitate suits: sensitive, dry, normal, combination.
What is Ascorbyl Tetraisopalmitate and what does it do in cosmetics?
Oil-soluble vitamin C derivative.
What's the INCI name for Ascorbyl Tetraisopalmitate?
The INCI name is Ascorbyl Tetraisopalmitate. It may also appear as: Tetrahexyldecyl Ascorbate, THD Ascorbate.
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