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Vitamin C derivative (antioxidant)

Ethyl Ascorbic Acid

INCI: 3-O-Ethyl Ascorbic Acid·Studied at 1–5%·Moderate evidence

An etherified, water-soluble vitamin C derivative that is more stable than L-ascorbic acid and converts to ascorbic acid in skin, studied for antioxidant support and the appearance of brightness and even tone. Its ether linkage protects the vitamin C from oxidising as quickly as the pure acid, letting it formulate at a wider pH range without the stinging L-ascorbic acid is known for. It is less studied on its own than L-ascorbic acid, so its case rests on being a stable, well-tolerated way to deliver vitamin C benefits rather than on a distinct mechanism.

Studied for

  • ·The appearance of brighter, more even-looking skin
  • ·The look of reduced dark spots
  • ·Antioxidant support against visible environmental dullness
  • ·The look of a smoother, more refined-looking surface with continued use

How it’s thought to work

An ethyl-ether of ascorbic acid studied for brightness-related appearance benefits; it is more stable and less pH-fussy than L-ascorbic acid, though the direct evidence is more limited than for the pure form. Skin enzymes cleave the ethyl group over time to release active ascorbic acid, a slower release thought to make it gentler on sensitive skin.

Landmark study· studied at 30% 3-O-ethyl-l-ascorbic acid

In lab skin cell and tissue models, a serum with this vitamin C derivative supported collagen production and a reduction in visible melanin.

The Anti-Ageing and Whitening Potential of a Cosmetic Serum Containing 3-O-ethyl-l-ascorbic Acid. Life (Basel), 2021.

View on PubMed (PMID 33946734) ↗

Questions

Is ethyl ascorbic acid as effective as L-ascorbic acid?
It converts to the same active ascorbic acid in skin and is much more stable, but it has a thinner direct research record, so it is best thought of as a well-tolerated, shelf-stable way to get vitamin C rather than a proven equal.
Does it need to be stored a certain way?
It is more stable in air and light than L-ascorbic acid, so it is more forgiving of everyday storage, though keeping any vitamin C serum away from direct heat and sun helps it last.
Can I use it with niacinamide?
Yes. Unlike L-ascorbic acid, which some formulators avoid pairing with niacinamide at low pH, the stability of this derivative makes it a common partner for niacinamide in the same product.

Serums we’ve scored with Ethyl Ascorbic Acid

References