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Ingredient · INCI reference

3-O-ethyl Ascorbic Acid

3-O-ethyl ascorbic acid is a stable, water-soluble derivative of vitamin C used as an antioxidant and skin-brightening ingredient in skincare.

What it is

This is a vitamin C derivative in which an ethyl group is attached at the 3 position of ascorbic acid, giving it better stability than pure ascorbic acid while remaining water soluble. It is used for its antioxidant activity and for an even-tone, brightening cosmetic effect. Its improved stability makes it easier to formulate in water-based products such as sunscreens and serums.

Safety & warnings

3-O-ethyl ascorbic acid is generally well tolerated, though as an acid-derived active it may cause mild tingling or irritation in sensitive individuals, particularly at higher concentrations or low pH. It is not a known fragrance allergen.

Origin & sourcing

Synthetic, produced by chemically modifying ascorbic acid (vitamin C) with an ethyl group.

Questions everyone asks

How is 3-O-ethyl ascorbic acid different from regular vitamin C?

It is a more stable, water-soluble vitamin C derivative that resists degradation better than pure ascorbic acid while offering antioxidant and brightening benefits.

Can it be used alongside sunscreen?

Yes, it is often included in sun care and daytime products as an antioxidant that complements UV protection.

Sources & references

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