INCI Name
2-O-ETHYL ASCORBIC A...
Functions
1 Roles
Sustainability
6/10
Category
actives
What It Does
2-O-Ethyl Ascorbic Acid (commonly referred to as 3-O-Ethyl Ascorbic Acid in trade nomenclature) is a water-soluble, stabilized derivative of L-ascorbic acid in which an ethyl group is bonded at the 3-O position of the ascorbic acid molecule, protecting it from rapid oxidative degradation that plagues pure vitamin C. This structural modification grants it exceptional stability across a broader pH and temperature range compared to L-ascorbic acid, while the ethyl ether bond is cleaved enzymatically in the skin to release free ascorbic acid, enabling effective tyrosinase inhibition and antioxidant activity. Formulators favor it for its dual water-solubility and skin-penetration efficiency, its compatibility with a wide range of cosmetic systems, and its ability to deliver brightening and anti-aging benefits at relatively low use concentrations (typically 1–3%) without the formulation challenges associated with pure ascorbic acid.
Technical Properties
pH Range
4.5-6.5
Optimal working range
Ionic Charge
nonionic
Molecular charge type
Viscosity Effect
neutral
Impact on formula thickness
Foaming Ability
none
Lather generation
Molecular Profile
Molecular Weight
204.18
g/mol
LogP
-0.90
Partition coefficient (lipophilicity)
H-Bond Donors
3
Hydrogen bond donor count
H-Bond Acceptors
6
Hydrogen bond acceptor count
Polar Surface Area
96.2
Angstroms squared
Ingredient Compatibility
Known Interactions
Benzoyl Peroxide oxidizes L-Ascorbic Acid, rendering both ingredients inactive. These must never be combined.
Hydrogen Peroxide rapidly oxidizes Ascorbic Acid, deactivating both. Strong oxidizer + antioxidant neutralization.
Ascorbic Acid reduces Cu2+ to Cu1+, deactivating copper peptides and generating free radicals via Fenton-like reactions. These must not be combined.
Ascorbic Acid reduces Cu2+ in GHK-Cu to Cu1+, deactivating the peptide complex and generating reactive oxygen species. Never combine in the same formulation.
Niacinamide and L-Ascorbic Acid can interact at low pH, potentially forming nicotinic acid (causes flushing). They work optimally at different pH ranges (Niacinamide pH 5-7, Ascorbic Acid pH 2.5-3.5). Consider using a Vitamin C derivative stable at higher pH, or separate products.
Retinol and L-Ascorbic Acid both require low pH but Retinol is unstable in acidic conditions. Using both in the same formula reduces efficacy of both actives. Separate into AM (Vitamin C) and PM (Retinol) products.
Ascorbic Acid can degrade Cyanocobalamin (Vitamin B12) in solution, converting it to inactive analogues. In liquid/gummy formulations, use Methylcobalamin or separate the vitamins. Tablet/capsule forms are less affected.
Ascorbic Acid + Sodium Benzoate can form benzene (a carcinogen) in acidic conditions with heat or UV exposure. This is a well-documented FDA concern in beverages. Use alternative preservatives or ensure pH > 4 and avoid metal catalysts.
Sodium Hyaluronate may thin in viscosity at the low pH required for L-Ascorbic Acid (pH < 3.5). Consider using a lower molecular weight HA or a Vitamin C derivative stable at higher pH.
Iron from iron oxide pigments can catalyze oxidation of Ascorbic Acid via Fenton reaction. Not a concern at typical pigment levels in tinted products, but avoid high concentrations of both.
Arbutin is most stable and effective at pH 5-7, while L-Ascorbic Acid requires pH 2.5-3.5. Combined use forces a pH compromise that reduces efficacy of one or both. Use an Ascorbic Acid derivative if combining.
Ascorbic Acid can accelerate Thiamine (B1) degradation in solution at acidic pH. In liquid supplements, this can reduce B1 potency over shelf life. Dry forms are unaffected.
Sustainability Profile
Sustainability Score
Biodegradability
inherently biodegradable
Source
synthetic
Feedstock
Synthesized from L-ascorbic acid (typically derived from glucose fermentation) via selective ethylation at the 3-O position
Quick Reference
- Full INCI Name
- 2-O-ETHYL ASCORBIC ACID
- Common Name
- 3-O-Ethyl Ascorbic Acid
- Category
- actives