Two products with “vitamin C” on the label often do not show the same molecule in their ingredient lists: it can be Ascorbic Acid, Ethyl Ascorbic Acid, Ascorbyl Palmitate or Magnesium Ascorbyl Phosphate. The form determines stability and how the percentage should be read.
In short: Ethyl Ascorbic Acid (3-O-ethyl ascorbic acid) is a stable derivative of ascorbic acid, which is pure vitamin C. Ascorbic acid oxidises easily on contact with air; derivatives are developed to improve stability and penetration into the skin. Their percentages are not directly comparable to those of ascorbic acid. Glow Me Like You Do, with 7% Ethyl Ascorbic Acid, is used in the morning; Love In Blue This Time, with 2% Ethyl Ascorbic Acid, is used primarily in the evening.
| INCI name | Ethyl Ascorbic Acid (3-O-Ethyl Ascorbic Acid) |
|---|---|
| What it does | Antioxidant support; radiance and the look of dullness and uneven tone |
| Who it is for | Glow Me Like You Do: sensitive, combination, normal · Love In Blue This Time: sensitive, dry, normal |
| When | Glow Me Like You Do every morning; Love In Blue This Time primarily in the evening |
| Sun protection | Does not replace sunscreen; the last step in the morning is sunscreen |
| Using it with others | Fine with a hydrating serum and moisturiser; Love In Blue This Time is not used on the same evening as AHA/BHA; for ordering with acids, see the linked guide |
| At s'hevec | Three facial skincare products, two of them with a declared concentration; also Roll-On The Floor for the underarms (no stated concentration). Details in the table below |
What does vitamin C do for the skin?
Vitamin C is described as one of the well-known antioxidants in the skin. A 2017 review summarises its topical use as follows: antioxidant support against oxidative stress, help in fading the look of dark spots, and support for the look of firmness; it is also described as the main molecule that recycles vitamin E. The same review also sets out the limits: studies in people on the efficacy of topical formulas are still limited, and the real challenge is finding a formula that is both stable and penetrates the skin well.
What is the difference between ascorbic acid and vitamin C derivatives?
The difference lies in stability and penetration into the skin. Pure ascorbic acid (L-ascorbic acid) oxidises easily on contact with air, and its physicochemical properties are not ideal for penetrating the skin. Chemically modified derivatives have been developed to improve stability, penetration and overall efficacy; a 2022 review assesses the differences between vitamin C derivatives developed for cosmetic use and their efficacy.
What is Ethyl Ascorbic Acid?
Ethyl Ascorbic Acid is ascorbic acid with an ethyl group attached to the oxygen at position 3; the “3-O-ethyl” in its name describes this structure. A 2019 laboratory study on pig skin observed that this derivative passed into the skin with common solvents such as 1,2-hexanediol, glycerin, propylene glycol and 1,2-pentanediol; the researchers noted that even simple formulas can carry it into the skin.
This is a finding about penetration, not an efficacy result. All four of these solvents (Pentylene Glycol, Propylene Glycol, Glycerin, 1,2-Hexanediol) appear in the ingredient list of Glow Me Like You Do; Love In Blue This Time contains the three other than propylene glycol.
Is a vitamin C derivative as effective as pure vitamin C?
There is no one-sentence answer: derivatives are developed for stability, while efficacy varies from derivative to derivative and from formula to formula. This is why the concentration is read together with the stability of the formula.
Which vitamin C derivative is in s'hevec products, and at what concentration?
| Product | Ethyl Ascorbic Acid | Position in the INCI list | Role in the routine |
|---|---|---|---|
| Glow Me Like You Do Vitamin C Serum | 7%, key active | 2nd, after water | Morning; amber glass pump bottle; radiance and dullness |
| Love In Blue This Time Ceramide and Copper Peptide Serum | 2%, with 2% ceramide complex | 3rd, after niacinamide | Primarily evening; barrier support and the look of fine lines |
| Power De-Puff Girls Eye Serum | Vitamin C derivative (ethyl ascorbic acid), supporting ingredient with no stated concentration | 6th | Eye area; the featured ingredients are caffeine and baobab extract |
| Roll-On The Floor Brightening Roll-On | Vitamin C derivative (3-O-Ethyl Ascorbic Acid), no stated concentration | 8th | Underarms; antiperspirant roll-on, for a radiant, even-looking tone |
Which one is enough depends on your priority. If the priority is the look of dullness and uneven tone, Glow Me Like You Do is built for this need; it makes no claim about fine lines. If the priority is barrier support and the look of fine lines, Love In Blue This Time already carries the derivative, so there is no need to add a separate vitamin C serum in the evening. The position in the ingredient list gives no information about concentration. Other s'hevec products for the look of dullness and uneven tone can be found in our collection of products for radiance.
When and with which products is a vitamin C derivative used?
Glow Me Like You Do is applied in the morning, before a hydrating serum, and the routine ends with moisturiser and sunscreen; for the steps, see our guide how to use a vitamin C serum. Using it with niacinamide is covered in our article can niacinamide and vitamin C be used together, and ordering with acids in our guide using active ingredients together.
Can Ethyl Ascorbic Acid be used on sensitive skin, and does it have side effects?
The skin types recommended on the labels of Glow Me Like You Do and Love In Blue This Time include sensitive skin; because our source list contains no study assessing the tolerance of this derivative, we make no general tolerance claim.
- Test on a small area first: the AAD recommends trying a new product on a small area before using it on the face; the steps are in our guide on how to test a product. If redness or itching appears during the test, do not go on to use the vitamin C serum on your face.
- Tingling: Glow Me Like You Do may cause a mild tingling in the first days; if the stinging continues or is accompanied by burning or redness, stop using it.
- Eyes and irritated skin: both facial serums are kept away from the eye area and are not applied to irritated skin.
- Pregnancy and medication: If you are pregnant or breastfeeding, or have a skin condition, consult your doctor before use. If you take medication regularly, ask your doctor about this too before starting a serum with a vitamin C derivative.
How should a vitamin C product be stored?
By limiting contact with light and air. This is why Glow Me Like You Do comes in an amber glass pump bottle; store it in a cool, dry place away from direct sunlight. Power De-Puff Girls should be used within 12 months of opening.
Frequently asked questions
Are Ethyl Ascorbic Acid and 3-O-Ethyl Ascorbic Acid the same thing?
Yes, both are names for the same molecule; both spellings are seen in ingredient lists.
Does Glow Me Like You Do contain vitamin E?
No. Vitamin E (Tocopherol) is not in its ingredient list; the supporting ingredients are 8D hyaluronic acid, panthenol, allantoin and Lubrajel Marine.
Can I use two serums with vitamin C derivatives on the same day?
Because Glow Me Like You Do is for the morning and Love In Blue This Time is primarily for the evening, the two fall at different times of day. Do not use Love In Blue This Time on the same evening as pure vitamin C serums or products containing AHAs/BHAs.
Can a vitamin C derivative be applied around the eyes?
Facial serums are kept away from the eye area. Power De-Puff Girls, which is formulated for the eye area, is applied by patting, without contact with the eyes.
Sources
- Al-Niaimi F et al. Topical Vitamin C and the Skin: Mechanisms of Action and Clinical Applications. J Clin Aesthet Dermatol. 2017.
- Enescu CD et al. A review of topical vitamin C derivatives and their efficacy. J Cosmet Dermatol. 2022.
- Iliopoulos F et al. 3-O-ethyl-l-ascorbic acid: Characterisation and investigation of single solvent systems for delivery to the skin. Int J Pharm X. 2019.
- American Academy of Dermatology (AAD). How to test skin care products.
This content is for information only and does not replace medical advice. s'hevec products are cosmetic products and are not intended for medical treatment. It was prepared by the s'hevec Team on the basis of the s'hevec product data library and the sources listed above.
