Ascorbyl Stearate
AKA “L-Ascorbic acid, 6-octadecanoate, L-Ascorbic acid monostearate, vitamin c stearate, INS NO.305, E-305, INS-305, L-ASCORBYL 6-OCTADECANOATE, ASCORBYL STEARATE [USP-RS], STEARIC ACID, 6-ESTER WITH L-ASCORBIC ACID”
Antioxidant
Ingredient Facts
Ascorbyl stearate
AKA: L-Ascorbic acid, 6-octadecanoate, L-Ascorbic acid monostearate, Vitamin c stearate, INS NO.305, E-305, INS-305, L-ASCORBYL 6-OCTADECANOATE, ASCORBYL STEARATE [USP-RS], STEARIC ACID, 6-ESTER WITH L-ASCORBIC ACID
Antioxidant · Antioxidant · EWG: 1
Plant-Derived
Antioxidant
Vitamin C
Clean
Ascorbyl stearate is a fatty acid ester.
Formula
C24H42O7
Mol. Weight
442.60
CAS #
25395-66-8
Form
Liquid
See origin →
Functions
Antioxidant
Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.
Neutralizes Free Radicals
Traditional Use
Created as a lipid-soluble form of vitamin C in the late 20th century to improve stability and allow incorporation into emollient formulations while maintaining antioxidant activity.
Skin Types
●all-skin-types, gentle
Best For
Sun Damage
Pregnancy & Breastfeeding Safe
Yes
Amended Final Report on the Safety Assessment of Hydroxystearic Acid
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of Ascorbyl Palmitate, Ascorbyl Dipalmitate, Ascorbyl Stearate, Erythorbic Acid, and Sodium Erythorbate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of Isostearic Acid
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of Oleic Acid, Lauric Acid, Palmitic Acid, Myristic Acid, and Stearic Acid
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report: Safety Assessment of Polyhydroxystearic Acid, Poly(3-Hydroxyoctanoic Acid, and Polylactic Acid as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Re-evaluation: Safety Assessment of Hydroxystearic Acid as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
10-Hydroxystearic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Ascorbyl Stearate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Polyhydroxystearic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Stearic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Final report of the safety assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and
Elmore AR
International journal of toxicology, 2005
Final report of the safety assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and
Elmore AR
International journal of toxicology, 2005
Final report of the safety assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and
Elmore AR
International journal of toxicology, 2005
Final report of the safety assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and
Elmore AR
International journal of toxicology, 2005
Ascorbyl Stearate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Hydroxystearic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Isostearic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Polyhydroxystearic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Stearic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Simultaneous contact sensitivity to hydroxystearic acid and C18-36 acid triglyceride in lip glosses.
Kimura M, Kawada A, Ogino M, Murayama Y
Contact dermatitis, 2002
Microemulsions based on TPGS and isostearic acid for imiquimod formulation and skin delivery.
Pescina S, Garrastazu G, Del Favero E, Rondelli V, Cantù L et al.
European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, 2018
Topical L-ascorbic acid: percutaneous absorption studies.
Pinnell SR, Yang H, Omar M, Monteiro-Riviere N, DeBuys HV et al.
Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.], 2001
Topical L-ascorbic acid: percutaneous absorption studies.
Pinnell SR, Yang H, Omar M, Monteiro-Riviere N, DeBuys HV et al.
Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.], 2001
Topical L-ascorbic acid: percutaneous absorption studies.
Pinnell SR, Yang H, Omar M, Monteiro-Riviere N, DeBuys HV et al.
Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.], 2001
Bio-derived hydroxystearic acid ameliorates skin age spots and conspicuous pores.
Schütz R, Rawlings AV, Wandeler E, Jackson E, Trevisan S et al.
International journal of cosmetic science, 2019
Bio-derived hydroxystearic acid ameliorates skin age spots and conspicuous pores.
Schütz R, Rawlings AV, Wandeler E, Jackson E, Trevisan S et al.
International journal of cosmetic science, 2019
Bio-derived hydroxystearic acid ameliorates skin age spots and conspicuous pores.
Schütz R, Rawlings AV, Wandeler E, Jackson E, Trevisan S et al.
International journal of cosmetic science, 2019
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR