FaceTheory Regena C20 Vitamin C Serum
A serum with 6 ingredients, including vitamin C.
This brightening serum is formulated around 3-O-Ethyl Ascorbic Acid and Ferulic Acid to brighten dull-looking skin and soften the look of wrinkles.
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What's inside
Key Ingredients
Benefits
Ingredients Explained
Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
It’s often used to:
Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.
Learn more about Propanediol3-O-Ethyl Ascorbic Acid is one of the most popular "stable" vitamin C derivatives in skincare.
Plain ascorbic acid is fantastic but notoriously fragile; it browns, oxidizes, and loses potency fast. So attaching an ethyl group to the third carbon of the molecule gives it some cool perks:
In a formula, it does the 3 classic vitamin C jobs: it acts as an antioxidant, helps brighten skin tone by inhibiting tyrosinase, and supports collagen.
The evidence is reasonably solid for a cosmetic ingredient; Liao and colleagues (2018) showed it's significantly more stable than ascorbic acid while still being effective.
A 2021 study by Zerbinati and colleagues tested a serum with 30% 3-O-ethyl-l-ascorbic acid and 1% lactic acid significantly increased collagen production, reduced UVB-induced DNA damage, and decreased melanin on a reconstructed pigmented skin model.
Typical real world usage sits around 0.5-5% (and 1-2% is common for daily serums).
Amounts up to 30% have been shown to be non-irritating on human skin samples, but two isolated cases reported allergic contact dermatitis so a patch test is sensible if you have reactive skin.
Learn more about 3-O-Ethyl Ascorbic AcidOlive Oil Polyglyceryl-4 Esters is an oil and isn't fungal acne safe.
We don't have a description for Dibutyl Lauroyl Glutamide yet.
We don't have a description for Dibutyl Ethylhexanoyl Glutamide yet.
Ferulic Acid is a plant based antioxidant that can be naturally found in the cell walls of grains like rice, oats, and corn. It has antioxidant and antimicrobial properties, and has the ability to boost the performance of other antioxidants as well.
A well-known study found that adding Ferulic Acid to a solution of Vitamins C and E doubled the photoprotection of skin. This is why you'll often see it paired with Vitamin C or Vitamin E serums rather than sold on its own.
A 2025 review of 18 human studies found that using Ferulic Acid (0.5-1%) daily for one to three months showed improvements in:
As far as allergies go, Ferulic acid is generally well-tolerated but can cause an allergic reaction in very rare cases. It's also worth noting that Ferulic acid is often extracted from plant sources like rice bran or wheat bran, so be sure to path test if you have known grain allergies.
Outside of skincare, researchers are also looking into Ferulic Acid for its potential benefits in areas like diabetes, Alzheimer's, and heart health.
Learn more about Ferulic AcidReviews
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Where it's from
FaceTheory is a British brand
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The data we've presented on this page has been verified by a member of the SkinSort Team.
Read more about us· Updated August 7, 2025 • Added by cakeT
