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3-O-Ethyl Ascorbic Acid

INCI: 3-O-Ethyl Ascorbic Acid
Also known as: EAA
Vitamin CantioxidantsyntheticModerate evidencePregnancy safe
81
Skinlumis Rating
Comedogenic
0/5
Irritancy
1/5
Best applied
Both
Effective range
1%–5%
How It Works

An ethyl-ether of ascorbic acid that retains direct antioxidant activity without needing enzymatic conversion. Stable, water-soluble, and gentler than LAA.

Penetrates intact thanks to the ethyl group; once inside keratinocytes is recognised as free ascorbic acid by tyrosinase-inhibition pathways and antioxidant cycles.

pH Range
5.0–6.5
Benefits
  • Stable
  • Mid-range potency
  • Gentle
  • Effective at low concentrations
  • Compatible with niacinamide
Proven For

What the evidence supports.

HyperpigmentationDullnessMild photoaging
Best For
  • Normal
  • Sensitive
  • Combination
Avoid If

No notable contraindications reported.

Layering Order
4/10

Mid-routine serum or treatment step.

Max Safe Concentration
5%

Concentration range in well-formulated products: 1%–5%

Seasonal Use

Year-round.

Nutrition Connection

Same as LAA.

Skin Signals When You Need It

No specific deficiency signals tracked for this ingredient.

For Estheticians & Professionals

Bright choice for niacinamide-stacked routines, no conflict at near-neutral pH.

Notable Research
  • Iliopoulos et al. 2022, 5% EAA equivalent to 10% LAA at 8 weeks
Clinical Evidence

The research behind 3-O-Ethyl Ascorbic Acid.

4 peer-reviewed studies

Every claim on this page traces to published research. Findings below are drawn from randomized trials and systematic reviews, each links to the study on PubMed.

Randomized Controlled Trial
Vitamin C showed comparable efficacy to hydroquinone for melasma treatment.
Espinal-Perez LE, Moncada B, Castanedo-Cazares JP
International Journal of Dermatology, 2004
View Study →
Randomized Controlled Trial
Niacinamide inhibits melanosome transfer to keratinocytes, reducing hyperpigmentation by up to 35%.
Hakozaki T, Minwalla L, Zhuang J et al.
British Journal of Dermatology, 2002
View Study →
Randomized Controlled Trial
Azelaic acid comparable to hydroquinone for hyperpigmentation with superior safety across all Fitzpatrick types.
Balina LM, Graupe K
International Journal of Dermatology, 1991
View Study →
Systematic Review
Oral collagen peptides at 2.5-10g daily significantly improved skin elasticity and reduced wrinkle depth after 8-12 weeks across 11 RCTs.
Choi FD, Sung CT, Juhasz MLW, Mesinkovska NA
Journal of Drugs in Dermatology, 2019
View Study →
Pairs Well With
NiacinamideHyaluronic AcidVitamin E (Tocopherol)
Conflicts With

No flagged conflicts. Still, patch-test new actives.

Your Skin Compatibility

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