With a high-concentration niacinamide serum, three things determine the results and the comfort: its place in the routine, how often you use it each day and the other actives used on the same evening. The steps below are based on the formula data and directions for use of Hi Girls Bye Pores.
In short: Apply 3–4 drops of niacinamide serum 1–2 times a day, after cleansing and toner and before moisturiser; sensitive skin starts with once a day. Hi Girls Bye Pores contains 10% niacinamide and 0.5% zinc PCA. On salicylic acid toner evenings, the order is Slyc-Alright, serum, moisturiser. When the serum is used in the morning, the routine ends with sunscreen.
Which appearance concerns is Hi Girls Bye Pores for?
Hi Girls Bye Pores Pore Serum focuses on three appearance concerns and is formulated for combination, normal and oily skin:
- Pores: helping pores on the T-zone and around the nose look less noticeable.
- Sebum and shine: balancing the look of shine during the day.
- Tone: a more even-looking skin tone.
How niacinamide works on the skin and what else it is used for are covered in a separate guide, niacinamide's mechanism of action and uses.
How to use a niacinamide serum: step by step
A niacinamide serum belongs in the serum step, between toner and moisturiser.
- Cleanse. Wash and dry your face.
- If you use a toner, apply it first. The order stays the same on evenings when you use an acid toner.
- Take 3–4 drops. Spread the serum over the whole face, starting with the T-zone and the sides of the nose, where pores are most visible. Do not apply around the eyes. In case of contact with eyes, rinse thoroughly with water.
- Let it absorb. Work it in with light touches, and move on to the next step once the serum has absorbed.
- Moisturise. Finish the routine with moisturiser; in the morning, sunscreen follows, with make-up last.
How many times a day should you use a niacinamide serum?
Hi Girls Bye Pores is used 1–2 times a day: in the morning, in the evening or both. Sensitive and dry skin starts with once a day.
| Routine | Order |
|---|---|
| Morning | Cleanse → Hi Girls Bye Pores → moisturiser → sunscreen |
| Evening | Cleanse → Hi Girls Bye Pores → moisturiser |
| Salicylic acid toner evening | Cleanse → Slyc-Alright → Hi Girls Bye Pores → moisturiser |
What percentage should a niacinamide serum be? Is 10% niacinamide too much for sensitive skin?
There is no single right concentration; a percentage takes on meaning according to the product type and your skin's tolerance. A review of niacinamide states that its effects depend on concentration, provided that a sufficient amount reaches the skin. This is why looking only at the percentage on the label is not enough; the type of product and its place in the routine also come into the choice.
In the s'hevec range, the concentration varies by product type: Magic Foam Party and Glyc-Alright contain 2% niacinamide, while 10% niacinamide is found only in Hi Girls Bye Pores. For the whole range, see our niacinamide products collection. A table of concentrations by product is in the niacinamide guide linked above.
The skin types recommended on the label of Hi Girls Bye Pores are combination, normal and oily skin; if it is used on sensitive skin, the product directions advise starting at a low frequency, and a high concentration can cause temporary redness on sensitive skin. According to the safety report of the Cosmetic Ingredient Review (CIR) Expert Panel, niacinamide did not cause a stinging sensation in stinging tests on people, and no irritation was seen in irritation tests carried out at lower concentrations; these findings belong to the test conditions in the report and should not be read as results for this serum. The panel also did not consider it a sensitiser. For sensitive skin, the decision rule is as follows:
- Before first use, do a patch test on the inner forearm.
- Start with the frequency given in the section on how many times a day; add the second daily application once your skin is comfortable.
- If redness occurs, first reduce how often you use the serum; if it does not settle within days at the reduced frequency, stop using the serum.
Which products can be used with a niacinamide serum?
A niacinamide serum can be used in the same routine as a salicylic acid toner, a moisturiser and sunscreen. The main thing to watch is how many products in the same routine supply niacinamide.
- Salicylic acid toner: Slyc-Alright Salicylic Acid (BHA) Toner does not contain niacinamide; the toner takes care of build-up in the pore openings and the serum takes care of the look of sebum and tone, so the two products do not duplicate each other's work.
- Moisturiser: for all skin types, the silicone-free Any Time Of Day Water-Based Moisturising Cream is the last hydration step after the serum. This cream also contains niacinamide; if redness occurs, reduce how often you use the serum, not the cream.
- Glycolic acid toner: Glyc-Alright contains 2% niacinamide, so adding the serum on that evening is not necessary.
Hi Girls Bye Pores: what's in the formula?
Hi Girls Bye Pores is a 30 ml niacinamide serum; in its ingredient list (INCI), niacinamide comes second, straight after water (Aqua).
| Feature | Hi Girls Bye Pores |
|---|---|
| Key actives | 10% niacinamide + 0.5% zinc PCA |
| Patented ingredient | Dendriclear™ |
| Supporting ingredients | Lubrajel Marine, panthenol, 8D hyaluronic acid, allantoin |
| Skin type | Combination, normal, oily |
Niacinamide does most of the work in the formula; zinc PCA is the second ingredient aimed at the look of sebum and shine. What this ingredient is and where the evidence reaches its limits are covered in the article the role of zinc PCA in the skin.
The formula was updated in March 2026; it focuses on the look of pores for combination, normal and oily skin.
What does a niacinamide serum not do?
A niacinamide serum helps with the look of pores and shine; it does not change pore structure and does not exfoliate.
- It does not change pore structure. Pore size is largely structural; the serum does not make pores smaller, but helps them look less noticeable. Why pores become more visible is covered in a separate article.
- It does not dissolve blackheads. A study on samples taken from the skin's uppermost layer showed that niacinamide interacts with the keratin structure but does not behave like a keratolytic (exfoliant) ingredient in the traditional sense. Exfoliation aimed at build-up in the pore openings is the job of salicylic acid (BHA).
- It does not stop oiliness completely. It helps balance the look of sebum and shine.
Who should take care when using a niacinamide serum?
If your skin is irritated or peeling, do not apply the serum to that area; the starting rule for sensitive skin is in the percentage section above. If you are pregnant or breastfeeding, or have a skin condition, consult your doctor before use. If you use a product recommended by your doctor for a diagnosed skin condition, also ask whether the serum is suitable in the same routine.
Frequently asked questions
Should you use a niacinamide serum in the morning or the evening?
Either works. In the CIR safety report, niacinamide was not found to increase sensitivity to light, so it can also be part of your morning routine. When you use it in the morning, finish the routine with sunscreen.
Can a niacinamide serum and a salicylic acid toner be used on the same evening?
Yes. The order is Slyc-Alright, then Hi Girls Bye Pores once the toner has absorbed, and moisturiser last. At first, the toner is used 2–3 evenings a week; the FDA recommends sun protection for people using products that contain BHA. Slyc-Alright also contains a low-concentration AHA complex. AHAs can increase the skin's sensitivity to the sun: apply sunscreen every morning while using this product and for one week after you stop. If stinging or dryness occurs on those evenings, move the serum to the morning.
Can a niacinamide serum be used on blemish-prone skin?
It can; however, Hi Girls Bye Pores is not a product for blemishes, and it is aimed at the look of pores and shine. For blemish-prone skin, the step in the routine is Slyc-Alright; the order of the two products on the same evening is shown in the table above. You can find how the serum and toner fit into a weekly schedule in the guide a step-by-step routine for blemish-prone skin.
Can a niacinamide serum be used under make-up?
Yes. Once the serum has absorbed, continue with moisturiser and sunscreen, and apply make-up after these layers have settled.
Can a niacinamide serum be used on dry skin?
It can, but Hi Girls Bye Pores is formulated for combination, normal and oily skin. On dry skin, do not skip the moisturiser step after the serum.
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.
- Sjöberg T et al. Niacinamide and its impact on stratum corneum hydration and structure. Sci Rep. 2025.
- U.S. Food and Drug Administration (FDA). Beta Hydroxy Acids.
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.
