3-O-Ethyl Ascorbic Acid: The Vitamin C That Stays Stable

Skincare labels are full of long chemical names, and 3-O-ethyl ascorbic acid is one of the longest. Behind the name is one of our favourite forms of vitamin C. It keeps the benefits of the classic ingredient and loses most of the drawbacks.

What is 3-O-ethyl ascorbic acid?

It's vitamin C with a small ethyl group attached, in the exact spot where pure vitamin C tends to break down. That one change makes it much more stable in a formula, while your skin can still use it as vitamin C [1][2].

It dissolves in both water and oil to a degree, which helps it get into the skin, rather than just sitting on top [2].

Why it's worth knowing

• Stable. Pure ascorbic acid (L-ascorbic acid) degrades quickly in light and air, and can turn a serum orange and less effective within weeks. 3-O-ethyl ascorbic acid holds up far better, so each drop keeps working [1].
• Gets where it's needed. Studies of how it moves through skin show it reaches the skin well, which is what you want from a brightening ingredient [2].
• Kind to skin. It doesn't need the very low pH of pure vitamin C, so it's less likely to sting and suits sensitive and oily skin alike.
• Works on uneven tone. Like other forms of vitamin C, it slows tyrosinase, the enzyme that starts pigment production, for a brighter, more even-looking complexion over time [1].

Who it suits

• Skin that has found pure vitamin C too harsh or stingy
• Oily or breakout-prone skin that doesn't love heavy, oily textures
• Anyone with uneven tone or post-breakout marks who wants a steady, gentle daily ingredient
• Melanin-rich skin, where gentle and consistent always beats harsh and fast

How to use it

• Apply after cleansing and before moisturizer, morning or night.
• Always wear sunscreen by day. UV is the biggest trigger for new pigment.
• Combine it freely with niacinamide, hyaluronic acid and gentle exfoliating acids.
• Give it 8 to 12 weeks of steady use before judging results.

Where you'll find it at Gleamin

3-O-ethyl ascorbic acid is one of the two forms of vitamin C in our Superactive Serum, alongside sodium ascorbyl phosphate. It also works in our Clarifying Brightening Cleanser together with desert lime and lilly pilly, two Australian botanicals rich in vitamin C. You can shop both in our Amazon store.

New to vitamin C? Start with how vitamin C works for dark spots.

References

1. Al-Niaimi F, Chiang NYZ. "Topical vitamin C and the skin: mechanisms of action and clinical applications." Journal of Clinical and Aesthetic Dermatology (2017). PMC5605218
2. Iliopoulos F, Sil BC, Moore DJ, Lucas RA, Lane ME. "3-O-ethyl-l-ascorbic acid: characterisation and investigation of single solvent systems for delivery to the skin." International Journal of Pharmaceutics: X (2019).

This article is for general information and isn't medical advice. If you have a skin condition or concern, talk to a doctor or dermatologist.