# COSRX The Niacinamide 15 Serum for combination skin

**Lovi Fit: Average fit for combination skin.**
Combination Skin Fit: High · Effectiveness: High · Safety: Excellent.

Page: https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/combination-skin

The Lovi Fit is the same in every country; only the stores and prices differ, and the ones here are for Canada.

Brand: [COSRX](https://lovi.care/skincare/ca/brands/cosrx)
Category: [Serums and treatments](https://lovi.care/skincare/ca/best/serums)

This fit is calculated for the concerns frequently associated with combination skin: an oily T-zone, enlarged pores, and dry cheeks. For scores based on a full skin profile (12D face scan, goals, preferences), use the Lovi app.

Works for combination skin; other serums fit it better.

## Why this fit

- Offers moderate benefits for your combination skin, as niacinamide and zinc PCA help regulate sebum production and reduce acne lesions, addressing your oily shine concerns.
- Allantoin and trehalose provide additional soothing and hydrating effects, supporting overall skin comfort.
- The formula is safe for your skin, with no harsh ingredients and a good profile for combination skin.

## Fit by skin type

- [Oily skin](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/oily-skin): High
- [Dry skin](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/dry-skin): High
- [Combination skin](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/combination-skin): Average (this page)
- [Sensitive skin](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/sensitive-skin): High
- [Acne-prone skin](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/acne-prone-skin): High
- [Skin with dark spots](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/dark-spots): High
- [Mature skin](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/mature-skin): High
- [Dry sensitive skin](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/dry-sensitive-skin): High
- [Oily acne-prone skin](https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/oily-acne-prone-skin): High

## Key ingredients

Niacinamide, Acetyl Glucosamine, Zinc Pca, Trehalose, Allantoin

## What the research says

- Topical nicotinamide plus an antibacterial adhesive agent and zinc-pyrrolidone carboxylic acid combined with adapalene significantly reduced noninflammatory acne lesions by the second week of therapy compared to placebo with adapalene in patients with moderate acne vulgaris. ([The Journal of Clinical and Aesthetic Dermatology, 2020](https://pubmed.ncbi.nlm.nih.gov/32983333/))
- Sodium trehalose sulfate decreased transepidermal water loss and increased stratum corneum water content in participants with low stratum corneum water content when applied for 4 weeks compared to placebo. ([Skin Research and Technology, 2024](https://pubmed.ncbi.nlm.nih.gov/38606717/))
- A topical gel containing chitosan, chlorhexidine, allantoin, and dexpanthenol significantly reduced postoperative pain, trismus, swelling, and analgesic consumption, while improving wound healing after third molar surgery compared to a placebo. ([Medicina Oral, Patologia Oral Y Cirugia Bucal, 2020](https://pubmed.ncbi.nlm.nih.gov/32683390/))
- Topical treatment with Thealoz Duo significantly improved dry eye disease symptoms, tear break-up time, and restored tear lipid layer functionality by reducing inflammatory response proteins in moderate to severe dry eye patients over 56 days. ([Journal of Clinical Medicine, 2025](https://pubmed.ncbi.nlm.nih.gov/40807147/))
- Topical post-laser application of human adipocyte-derived mesenchymal stem cell media combined with niacinamide significantly improved wrinkle index, melanin index, patient satisfaction, and investigator esthetic improvement scores compared to vehicle cream in patients with aging skin. ([Journal of Cosmetic Dermatology, 2021](https://pubmed.ncbi.nlm.nih.gov/33103316/))
- Topical nicotinamide prevented solar-simulated UV-induced immunosuppression in healthy volunteers, and men experienced immunosuppression at solar-simulated UV doses three times lower than those required for women. ([The Journal of Investigative Dermatology, 2008](https://pubmed.ncbi.nlm.nih.gov/17882270/))
- Topical 5% niacinamide applied twice daily for 12 weeks reduced fine lines and wrinkles, hyperpigmented spots, red blotchiness, and skin sallowness, and improved skin elasticity compared to vehicle control in 50 female white subjects with facial photoaging. ([Dermatologic Surgery, 2005](https://pubmed.ncbi.nlm.nih.gov/16029679/))
- Topical 2% N-acetyl glucosamine reduced facial hyperpigmentation in an 8-week split-face clinical test, with an even greater effect observed when combined with 4% niacinamide. ([Journal of Cosmetic Dermatology, 2007](https://pubmed.ncbi.nlm.nih.gov/17348991/))
- N-acetyl-glucosamine-loaded nanostructured lipid carriers successfully delivered the hydrophilic agent through the skin and reduced melanin distribution in healthy volunteers. ([Advanced Pharmaceutical Bulletin, 2016](https://pubmed.ncbi.nlm.nih.gov/28101465/))
- Topical cosmetic products containing hyaluronic acid, N-acetyl glucosamine, and gamma-amino butyric acid improved skin hydration by 24.28% to 33.60%, elasticity by 11.98%, and skin lightening by 5.26% over 2 months in 20 female participants. ([Journal of Cosmetic and Laser Therapy, 2019](https://pubmed.ncbi.nlm.nih.gov/30040516/))
- Zinc PCA inhibits UVA-induced matrix metalloproteinase-1 production through suppressed AP-1 activation and enhances type I collagen synthesis by increasing SVCT2 mRNA expression in cultured normal human dermal fibroblasts. ([International Journal of Cosmetic Science, 2012](https://pubmed.ncbi.nlm.nih.gov/21834944/))
- Topical chloramphenicol-betamethasone combined with sodium hyaluronate/trehalose/carbomer gel compared to chloramphenicol-betamethasone alone reduced most subjective symptoms at 1 week but increased blurred vision at 4 weeks following strabismus surgery in 31 patients, with no significant differences in conjunctival inflammation between treatments. ([Journal of Ocular Pharmacology and Therapeutics, 2019](https://pubmed.ncbi.nlm.nih.gov/31298607/))
- An injectable product combining different molecular weights of hyaluronic acid and trehalose reduced CML formation by 45% at baseline and 30% under methylglyoxal-induced stress while preserving cell viability in human skin explants compared to untreated controls. ([International Journal of Molecular Sciences, 2025](https://pubmed.ncbi.nlm.nih.gov/40244036/))
- Combining trehalose with dimethyl sulfoxide improves human fetal skin cryopreservation, resulting in 65% membrane integrity and graft performance indistinguishable from fresh unfrozen skin in immunodeficient mice compared to lower integrity with glycerol or dimethyl sulfoxide alone. ([Cryobiology, 2002](https://pubmed.ncbi.nlm.nih.gov/12237087/))
- Topical gel containing chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol did not improve postoperative comfort regarding swelling and pain, but improved the wound's aesthetic appearance following impacted lower third molar extraction compared to no gel. ([Medicina Oral, Patologia Oral Y Cirugia Bucal, 2016](https://pubmed.ncbi.nlm.nih.gov/27475700/))
- An overnight patch containing Allium cepa extract and allantoin safely promotes scar healing after dermatologic surgery, resulting in significantly greater reductions in observer- and patient-assessed POSAS scores compared to no treatment. ([Aesthetic Plastic Surgery, 2018](https://pubmed.ncbi.nlm.nih.gov/29948103/))
- Prophylactic application of a topical scar gel containing Allium cepae extract, allantoin, and heparin significantly improves patient-assessed scar color, stiffness, and irregularity compared to no treatment in women following a cesarean section. ([Journal of Drugs in Dermatology, 2014](https://pubmed.ncbi.nlm.nih.gov/24509969/))

## What reviewers say

This serum is widely praised by users with oily and acne-prone skin for its ability to significantly control sebum and refine pore texture, often delivering a smoother, "glass skin" finish. The high 15% concentration is effective for many, but frequently causes irritation, stinging, or barrier damage for those with sensitive or dry skin types. This summary is based on a very large amount of data and should be definitely taken into account.

- Liked: Controls excess oil (mostly mentioned)
- Liked: Lightweight absorption (often mentioned)
- Liked: Reduces pore visibility (often mentioned)
- Liked: Smoothes skin texture (often mentioned)
- Liked: Fades acne marks (sometimes noted)
- Disliked: Causes irritation (sometimes noted)
- Disliked: Too strong (sometimes noted)
- Disliked: Drying effect (rarely noted)
- Disliked: Induces breakouts (rarely noted)

## How to apply

- Use your serum as part of your PM routine. Start using it 3 times a week and move to daily use if your skin likes it.
- Apply the serum after cleansing and toner, and right before your moisturizer.
- Gently press 2-3 drops of the serum into your skin and wait a minute ⏳for it to soak in.
- Apply the serum on clean and dry skin since your skin is not sensitive.
- Always do a patch test before using the serum for the first time, and avoid the eye area .
- Video: https://storage.pora.ai/c879dda8655a61c19d3d8c9ebad6b06d.mp4

## Questions and answers

### How well does COSRX The Niacinamide 15 Serum work for combination skin?

COSRX The Niacinamide 15 Serum offers moderate benefits for combination skin, as ingredients like niacinamide and zinc PCA help control oily shine and soothe the skin. To work best for this skin type, a treatment needs effective ingredients like niacinamide and propolis that provide balanced hydration and radiance without causing excess oiliness or dryness.
Sources: [The Journal of Clinical and Aesthetic Dermatology, 2020](https://pubmed.ncbi.nlm.nih.gov/32983333/), [Skin Research and Technology, 2024](https://pubmed.ncbi.nlm.nih.gov/38606717/)

### Which ingredients make this serum a good fit for combination skin?

This serum works for combination skin because niacinamide and zinc PCA help control oily shine, while allantoin and trehalose soothe and calm dry areas. To be an even better fit for this skin, a treatment of this type needs ingredients like propolis to enhance radiance and provide balanced hydration without excess oiliness.
Sources: [The Journal of Clinical and Aesthetic Dermatology, 2020](https://pubmed.ncbi.nlm.nih.gov/32983333/), [Skin Research and Technology, 2024](https://pubmed.ncbi.nlm.nih.gov/38606717/)

### What does Niacinamide do for combination skin?

Niacinamide helps balance oily areas by reducing excess shine and pore size while keeping dry patches hydrated and smooth. It also works to calm redness and even out skin tone, making it very suitable for combination skin.
Sources: [The British Journal of Dermatology, 2002](https://pubmed.ncbi.nlm.nih.gov/12100180/), [Antioxidants, 2021](https://pubmed.ncbi.nlm.nih.gov/34439563/)

### What does Acetyl Glucosamine do for combination skin?

Acetyl Glucosamine helps keep combination skin hydrated and smooth while evening out dark spots and patchiness. It also increases water content and supports skin renewal, making dry areas feel soft and oily zones balanced.
Sources: [Journal of Cosmetic Dermatology, 2007](https://pubmed.ncbi.nlm.nih.gov/17348991/), [The British Journal of Dermatology, 2010](https://pubmed.ncbi.nlm.nih.gov/19845667/)

### Where does this serum go in a skincare routine for combination skin?

This serum goes in your evening routine after cleansing and toning, and before moisturizing. Combination skin works best with products that balance oily shine with lightweight soothing ingredients and gentle hydration.
Sources: [International Journal of Cosmetic Science, 2020](https://pubmed.ncbi.nlm.nih.gov/31461548/)

### Can I use this serum with retinol, and in what order?

You can use this serum with retinol by applying the serum first in your evening routine, as the formula is safe and gentle on combination skin. Layering it beneath a retinoid treatment may help soothe the skin and reduce irritation while supporting overall comfort.
Sources: [Journal of Cosmetic Dermatology, 2024](https://pubmed.ncbi.nlm.nih.gov/38102855/)

### How often should I use this serum?

You can use this serum in your evening routine, as treatments fit well there for simplicity and extra safety around sun exposure. Combination skin generally benefits from a serum that balances oil production while keeping dry areas calm and hydrated with ingredients like niacinamide, zinc PCA, allantoin, and trehalose.
Sources: [The Journal of Clinical and Aesthetic Dermatology, 2020](https://pubmed.ncbi.nlm.nih.gov/32983333/), [Skin Research and Technology, 2024](https://pubmed.ncbi.nlm.nih.gov/38606717/)

### Can this serum clog pores, cause breakouts or purging for combination skin?

This serum is unlikely to clog pores or cause breakouts for combination skin, as it contains niacinamide and zinc PCA to help regulate oil and keep skin clear. However, reviewers sometimes report mild irritation or breakouts because the strength of the formula may feel too strong for some. A product for this skin needs balancing ingredients that control shine while keeping hydration gentle.
Sources: [The Journal of Clinical and Aesthetic Dermatology, 2020](https://pubmed.ncbi.nlm.nih.gov/32983333/)

### Is this serum fragrance-free and alcohol-free?

Yes, it has no fragrance and no drying alcohol.

## Alternatives for combination skin

- [Skin1004 Probio-Cica Intensive Ampoule](https://lovi.care/skincare/ca/p/skin1004/probio-cica-intensive-ampoule/for/combination-skin) — High fit — CA$24.44 at Amazon
- [Dr.Althea Vitamin C Boosting Serum](https://lovi.care/skincare/ca/p/dr-althea/vitamin-c-boosting-serum/for/combination-skin) — High fit — CA$27.99 at Amazon
- [COSRX The Vitamin C 23 Serum](https://lovi.care/skincare/ca/p/cosrx/the-vitamin-c-23-serum/for/combination-skin) — Average fit — CA$33.98 at Amazon

## Pairs well with

- Cleanser: [Fresh Soy Face Cleanser](https://lovi.care/skincare/ca/p/fresh/soy-face-cleanser/for/combination-skin) — Superior fit — CA$44.95 at Amazon
- Hydrating Toner: [Paula's Choice Pore-Reducing Toner](https://lovi.care/skincare/ca/p/paula-s-choice/skin-balancing-pore-reducing-toner/for/combination-skin) — Superior fit — CA$37.60 at Amazon
- Moisturizer: [COSRX Oil-Free Ultra-Moisturizing Lotion with Birch Sap](https://lovi.care/skincare/ca/p/cosrx/oil-free-ultra-moisturizing-lotion-with-birch-sap/for/combination-skin) — Superior fit — CA$29.98 at Amazon

## Where to buy

- Amazon.ca: CA$26.97 (https://www.amazon.ca/dp/B09ZYB8S31?tag=lovi-care-web-product01-20&linkCode=osi&th=1&psc=1)
- Sephora: CA$29.00 (https://www.sephora.com/ca/en/product/the-niacinamide-15-serum-P519126?skuId=2913192)
Prices checked 10 Oct – 3 Nov 2026.

## Ingredients

Water, Pentylene Glycol, Niacinamide, Butylene Glycol, Acetyl Glucosamine, 1,2-Hexanediol, Zinc Pca, Trehalose, Hydrolyzed Sclerotium Gum, Pullulan, Allantoin, Ethylhexylglycerin, Sodium Phytate, Tocopherol, Xanthan Gum, Citric Acid
## About the Lovi Fit

Lovi: Unbiased, science-based skincare AI trained on real user outcomes.

Lovi calculates every fit score from the full ingredient list with brand-independent rules its dermatologists and cosmetic chemists build and review, and personalizes every pick with AI trained on the real results of millions of users. Lovi trains its fit score models on a proprietary dataset built from more than 10,000 expert-labeled products and more than 100,000 simulated examples, following an internally consistent methodology presented at Cosmoprof, AMWC, and Skin of Color Update. Levels from best to worst: Superior, High, Average, Low, Caution, Warning.

Behind this fit score: Nadia Kapleva, MS (Co-founder, Medical Director); Alexey Shagraev, PhD (Co-founder, CEO and CTO); Dr. Sofía Perea Pérez, MD, MSc (Medical Board); Aishani Shah, MD (Medical Board); Asya Zubkova, MS (Medical Board); Hanna Kurets, MD (Medical Board, Medical Advisor); Elina Nazarenko, MD (Medical Board); Victoria Derkova, MS (Medical Board).

Page built Nov 8, 2026.

More from Lovi: https://lovi.care/skincare/llms.txt

## This page in other countries

- United States: https://lovi.care/skincare/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- United Kingdom: https://lovi.care/skincare/uk/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- Ireland: https://lovi.care/skincare/ie/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- Germany: https://lovi.care/skincare/de/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- France: https://lovi.care/skincare/fr/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- Italy: https://lovi.care/skincare/it/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- Netherlands: https://lovi.care/skincare/nl/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- Spain: https://lovi.care/skincare/es/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- Canada: https://lovi.care/skincare/ca/p/cosrx/the-niacinamide-15-serum/for/combination-skin (this page)
- Australia: https://lovi.care/skincare/au/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- Singapore: https://lovi.care/skincare/sg/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- Saudi Arabia: https://lovi.care/skincare/sa/p/cosrx/the-niacinamide-15-serum/for/combination-skin
- United Arab Emirates: https://lovi.care/skincare/ae/p/cosrx/the-niacinamide-15-serum/for/combination-skin