The idea that niacinamide and vitamin C weaken each other when used in the same routine is still widely repeated. Below you will find the rules for using the two ingredients on the same morning, at different times of day or in a single serum, and which one to set aside if your skin reacts.
In short: Yes, they can be used together. Morning order: Glow Me Like You Do (7% Ethyl Ascorbic Acid) → Hi Girls Bye Pores (10% niacinamide) → moisturiser → sunscreen. If you would rather use one serum instead of two, Love In Blue This Time contains niacinamide and 2% Ethyl Ascorbic Acid in the same formula and is intended mainly for the evening. If your skin is sensitive, let your skin get used to each product separately first.
| INCI name | Niacinamide; Ethyl Ascorbic Acid (3-O-ethyl ascorbic acid) |
|---|---|
| When | Glow Me Like You Do in the morning; Love In Blue This Time mainly in the evening; Hi Girls Bye Pores morning or evening |
| Frequency | Hi Girls Bye Pores 1–2 times a day, once a day on sensitive skin |
| Sun sensitivity | Niacinamide is not a photosensitiser (CIR); a vitamin C derivative does not replace sunscreen |
| At s'hevec | Glow Me Like You Do (7% Ethyl Ascorbic Acid), Hi Girls Bye Pores (10% niacinamide), Love In Blue This Time (both in the same formula) |
Can niacinamide and vitamin C be used together?
Yes; the two ingredients can share a routine and even the same bottle. Our source list does not include a study that directly examines the old “do not use them together” view, so we look at how formulas are made today. In the INCI list of Love In Blue This Time, Niacinamide comes second and Ethyl Ascorbic Acid third, straight after water. This order does not indicate concentrations; it shows that both ingredients are present in a single formula.
s'hevec products contain a derivative of ascorbic acid rather than pure ascorbic acid: pure ascorbic acid oxidises easily on contact with air, whereas Ethyl Ascorbic Acid was developed as a stable vitamin C derivative. We explain the differences between the derivatives in our article on vitamin C derivatives and Ethyl Ascorbic Acid, and what niacinamide does for the skin in our guide on what niacinamide is and what it does.
In what order do you apply niacinamide and vitamin C?
If you use separate products on the same morning, the vitamin C derivative serum goes on first, followed by the niacinamide serum. This order is based not on a study but on the directions for the two products: Glow Me Like You Do is applied after cleansing, while Hi Girls Bye Pores comes before moisturiser; if you use a toner, it comes before both serums.
- Vitamin C derivative. Spread 3–4 drops of Glow Me Like You Do over clean, dry skin, keeping it away from the eye area; let it absorb.
- Niacinamide. Spread 3–4 drops of Hi Girls Bye Pores over the whole face, starting with the T-zone.
- Moisturiser and sunscreen. The morning routine ends with sunscreen; make-up comes last.
| Approach | Morning | Evening | Who it suits |
|---|---|---|---|
| Same morning | Glow Me Like You Do, Hi Girls Bye Pores | Depending on your routine | People who already use both serums separately without any problems |
| Different times of day | Glow Me Like You Do | Hi Girls Bye Pores | Sensitive skin, beginners |
| Single serum | Moisturiser, sunscreen | Love In Blue This Time | Sensitive, dry, normal skin |
Two serums or one?
If you have two separate goals – radiance and the look of pores – two serums are the right choice; if you want barrier support and a simple evening routine, one serum is enough. You will find toners, serums and masks for radiance among our radiance products.
| Product | Key concentration | Time | Skin type |
|---|---|---|---|
| Glow Me Like You Do | 7% Ethyl Ascorbic Acid | Morning | Sensitive, combination, normal |
| Hi Girls Bye Pores | 10% niacinamide, 0.5% zinc PCA | 1–2 times a day | Combination, normal, oily |
| Love In Blue This Time | 2% ceramide complex, 2% Ethyl Ascorbic Acid | Mainly evening | Sensitive, dry, normal |
Glow Me Like You Do Vitamin C Serum is the morning step for dullness and the look of uneven tone. Hi Girls Bye Pores Pore Serum does not make pores smaller; it helps them look less noticeable. In Love In Blue This Time Ceramide and Copper Peptide Serum, niacinamide is a supporting ingredient with no stated concentration; if the look of pores is your focus, the single serum will not meet that need.
Do niacinamide and vitamin C cause side effects together, and who should take care?
Our sources contain no information showing that combining the two causes a reaction. Niacinamide is described as a well-tolerated ingredient; according to the CIR report, it did not cause stinging at the concentrations tested and was not found to be a significant irritant or sensitiser. Our sources contain no information on the tolerability of Ethyl Ascorbic Acid. If your skin reacts, narrow down the cause like this:
- Stinging or tingling: the directions for Glow Me Like You Do note that mild tingling is possible during the first few days. Set this serum aside first for a few days; if the stinging continues or comes with burning or redness, stop using it.
- Redness: a high niacinamide concentration can cause temporary redness on sensitive skin. Reduce Hi Girls Bye Pores to once a day or move it to the evening; if the redness continues, take a break.
- If the cause is unclear: stop both, then reintroduce them one at a time once your skin has calmed down.
- If you use acid products: Do not use Love In Blue This Time on the same evening as AHA or BHA toners and peels. For timing with acids, see the guide to using active ingredients together.
If you are pregnant or breastfeeding, or have a skin condition, consult your doctor before use. In that conversation, show which of the niacinamide and vitamin C derivative serums you plan to use and in what order.
Frequently asked questions
Can you go out in the sun after applying niacinamide and vitamin C?
Yes, as long as your routine ends with sunscreen. The CIR report states that niacinamide is not a photosensitiser; our sources contain no information on this for vitamin C derivatives. Serums do not replace sunscreen.
Can vitamin C be used in the evening?
It depends on the product. Glow Me Like You Do was designed for the morning, while Love In Blue This Time contains its vitamin C derivative in a formula intended mainly for the evening. If you use both on the same day, one goes in the morning and the other in the evening.
Can I mix the two serums in my palm and apply them together?
The directions describe the two serums as separate steps: the second is applied once the first has absorbed. Our sources contain no information on the effect of mixing them.
Do niacinamide and vitamin C help with the look of dark spots?
Both ingredients have been studied in relation to the look of uneven tone; the contribution of niacinamide to the look of uneven tone is described as concentration-dependent. Even so, pronounced dark spots are not the focus of Glow Me Like You Do.
Sources
- Wohlrab J et al. Niacinamide - mechanisms of action and its topical use in dermatology. Skin Pharmacol Physiol. 2014.
- Cosmetic Ingredient Review Expert Panel. Final report of the safety assessment of niacinamide and niacin. Int J Toxicol. 2005.
- Al-Niaimi F et al. Topical Vitamin C and the Skin: Mechanisms of Action and Clinical Applications. J Clin Aesthet Dermatol. 2017.
- 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.
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.
