What makes COSRX The Niacinamide 15 Serum different from typical niacinamide serums?

COSRX The Niacinamide 15 Serum uses a clinically tested 15% niacinamide concentration, higher than many standard serums, to give intensive breakout, pore, and oil control care. It is paired with zinc PCA for sebum balance, acetyl glucosamine for texture and dark spot refinement, and allantoin to help soothe sensitivity. The lightweight, non-comedogenic texture absorbs quickly without a tacky finish, making it easy to layer in a Korean skincare routine, and clinical data confirms meaningful improvements in pore count, oiliness, whiteheads, and blemish visibility within 4 weeks.

Is COSRX The Niacinamide 15 Serum suitable for sensitive or acne-prone skin?

Yes. COSRX The Niacinamide 15 Serum is designed specifically for oily and acne-prone skin and is clinically proven non-comedogenic, meaning it will not clog pores when used as directed. Niacinamide and zinc PCA work together to regulate oil and help prevent congestion, while acetyl glucosamine and allantoin support texture smoothing and comfort. Because the formula is high strength, patch testing and gradual introduction are recommended for more sensitive skin, but many users with acne-prone, reactive skin can achieve clearer, more even, glow-enhancing results over time.

Does COSRX The Niacinamide 15 Serum help with blemish scars and dark spots?

The Niacinamide 15 Serum is formulated to address both active breakouts and the marks they leave behind. The combination of 15% niacinamide and acetyl glucosamine targets uneven tone and discoloration from past blemishes, helping to visibly fade spots and refine texture. Clinical data for the serum shows measurable reductions in blemishes and pigmentation after 4 weeks of consistent use. When paired with daily sunscreen and a gentle Korean skincare routine, it supports clearer-looking skin and a more even, glass skin-like radiance over time.

How should I include COSRX The Niacinamide 15 Serum in my daily skincare routine and under makeup?

After cleansing and toning, apply 2–3 drops of COSRX The Niacinamide 15 Serum evenly across the face or onto areas prone to excess oil, enlarged pores, or blemish marks. Follow with a lightweight, barrier-supporting moisturizer. The fast-absorbing, non-sticky texture layers well under sunscreen and makeup, helping complexion products sit more smoothly as pores and texture improve. It can be used morning and/or night, but daily sunscreen is essential to maintain results and protect skin while brightening ingredients work.

Can I use COSRX The Niacinamide 15 Serum with vitamin C or retinol?

Because COSRX The Niacinamide 15 Serum is high strength, it is best not to introduce it at the same time as other strong actives like pure vitamin C or retinol in the same routine, especially on sensitive or compromised skin. Instead, alternate use on different days or separate high-strength products into morning and night to help minimize the risk of irritation. Pairing the serum with gentle hydrating layers, barrier-supporting creams, and daily sunscreen fits the Korean skincare approach to balanced, slow-aging care for clearer, smoother, more refined-looking skin.

COSRX The Niacinamide 15 Serum with dropper and molecular structure, featuring 15% niacinamide blended with Acetyl Glucosamine and Zinc PCA; clinically designed for acne-prone, oily skin to control sebum, reduce large pores, and smooth skin texture; compatible with exfoliating or brightening actives.

COSRX The Niacinamide 15 Serum displayed with text ‘15% of Niacinamide’, emphasizing its high concentration formula to target excess sebum, large pores, and uneven skin tone; suitable for for oily, acne-prone skin looking to even out skin tone.

Clinical infographic of COSRX The Niacinamide 15 Serum showing visible changes in 4 weeks including reduced acne, pores, blackheads, and oil; dermatology-tested Korean serum for oily and congested skin with improved tone and texture.

Model holding COSRX The Niacinamide 15 Serum with clinical claim of 24% redness reduction in 4 weeks; high-strength niacinamide formula proven to calm acne inflammation and even out post-blemish pigmentation on sensitive, oily skin.

Infographic showing COSRX The Niacinamide 15 Serum passing a non-comedogenic test by Dermacosmetic Skin Science Laboratory; verified not to clog pores and proven suitable for acne-prone skin, with safe daily use under makeup or actives.

Before and after photos from COSRX The Niacinamide 15 Serum clinical trial showing 15.5% blemish reduction and 19.47% pigmentation improvement after 4 weeks; niacinamide-based Korean serum targeting hyperpigmentation and acne marks.

Dermacosmetic laboratory test results of COSRX The Niacinamide 15 Serum proving 45.27% decrease in pore count, 48.07% less oiliness, and up to 50% reduction in whiteheads within 4 weeks; suitable for acne-prone, oily skin types.

Before-and-after user results showing visible reduction of acne scars and smoother skin after consistent use of COSRX The Niacinamide 15 Serum; formulated to minimize sebum and refine large pores while fading dark spots.

Key ingredient breakdown of COSRX The Niacinamide 15 Serum showing 15% niacinamide for brightening and texture improvement, Zinc PCA for oil control and acne care, Acetyl Glucosamine for exfoliation, and Allantoin for soothing.

Clinical study summary showing 100% of participants agree COSRX The Niacinamide 15 Serum improves acne spots, pores, and oil balance within 4 weeks; evidence-backed Korean serum for oily and acne-prone skin care routines.

Close-up of COSRX The Niacinamide 15 Serum texture showing clear, lightweight, non-sticky liquid consistency; formulated for oily, acne-prone skin to absorb quickly without residue, ideal for layering with exfoliating or brightening actives.

Infographic describing COSRX The Niacinamide 15 Serum’s active intensive acne care for all stages — preventing excess sebum and clogged pores, calming active acne, and reducing dark spots and post-acne scars through 15% niacinamide and Zinc PCA.

COSRX The Niacinamide 15 Serum recycling guide showing breakdown of silicon dropper head, PP plastic cap, PE wiper, and recyclable glass bottle; visual instruction promoting sustainable packaging disposal.

Routine step guide showing COSRX The Niacinamide 15 Serum as Step 2 in the #BlemishDermSerum routine, used after toner and before cream; suitable for acne-prone, oily skin to balance sebum and refine pores when layered with other actives.

Top-Fave

The Niacinamide 15 Serum

Name: The Niacinamide 15 Serum
Brand: COSRX Official
Price: 25.0 USD
Availability: InStock

Total Breakout Care & Oil Control

COSRX’s The Niacinamide 15 Serum is formulated with 15% niacinamide, paired with zinc PCA to deeply refine the appearance of pores, regulate excess sebum, and help reduce the look of post-acne marks. Ideal for oily, combination or blemish-prone skin, it delivers a clearer, smoother, more even complexion with continued use.

*Non-comedogenic tested - doesn't clog the pores.

Size : 20ml / 0.67 fl. oz

The Niacinamide 15 Serum (Quantity)

Single 2-Pack 3-Pack

$25.00

Quantity

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Recommended for
COSRX The Niacinamide 15 serum is for those with oily, combination, or acne-prone skin. It is particularly useful for individuals dealing with excess sebum production, enlarged pores, rough skin texture. It optimally combines 15% niacinamide with other ingredients and addresses all stages of acne, from the initial to the final stage, providing a comprehensive care solution.

Target concerns
- Bumpy skin
- Sebum oil
- Pores
- All stages of Acne
- Even skin tone
- Hyperpigmentation

Texture
Light and refreshing, it absorbs quickly without leaving any residue. It's easy to layer under other skincare products or makeup.

After cleansing, during the serum phase, apply a few drops to the skin. Use fingertips to gently massage and absorb the serum, starting from the center of the face working towards the edges.

* Highly concentrated serums should only be used in the evening? NO!
* This serum can be used in the morning and/or afternoon.
* If applied in the morning, be sure to use with a SPF of 30 or higher.

KEY INGREDIENTS

• Niacinamide :
Provides total acne care by controlling sebum production, soothing acne inflammation and diminishing post acne scars

• N-Acetylglucosamine(NAG) :
Works in synergy with niacinamide to effectively fade hyperpigmentation

• Zinc PCA :
Inhibits inflammation and promotes recovery of damaged skin

• Allantoin :
Promotes collagen synthesis to facilitate skin regeneration

Target concerns
- Bumpy skin
- Sebum oil
- Pores
- All stages of Acne
- Even skin tone
- Hyperpigmentation

Texture
Light and refreshing, it absorbs quickly without leaving any residue. It's easy to layer under other skincare products or makeup.

After cleansing, during the serum phase, apply a few drops to the skin. Use fingertips to gently massage and absorb the serum, starting from the center of the face working towards the edges.

* Highly concentrated serums should only be used in the evening? NO!
* This serum can be used in the morning and/or afternoon.
* If applied in the morning, be sure to use with a SPF of 30 or higher.

KEY INGREDIENTS

• Niacinamide :
Provides total acne care by controlling sebum production, soothing acne inflammation and diminishing post acne scars

• N-Acetylglucosamine(NAG) :
Works in synergy with niacinamide to effectively fade hyperpigmentation

• Zinc PCA :
Inhibits inflammation and promotes recovery of damaged skin

• Allantoin :
Promotes collagen synthesis to facilitate skin regeneration

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Overall rating: 4.5852275 / 5 from 1056 reviews.

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Review highlights

Reviews

Nighttime routine

"Serum feels light weight. It has helped with the lines on my face and the overall appearance of my skin. Love using it during my nighttime routine."

— Yvette M. (5/5)

"I’m concerned about the quality of the product I received, as it does not seem to be up to the standard I expected. I also noticed that the parcel had a shipping sticker from Mississauga, Ontario, even though I ordered directly from the official website and the tracking information indicated that the package was being shipped from the USA. This difference in shipping origin is concerning and raises some questions about the product’s source. In any case, my main concern is that the quality of the product does not seem satisfactory. I would appreciate it if you could please look into this and clarify the situation."

— PALASH (1/5)

I’ve been using the niacinamide

"I’ve been using the niacinamide for about 6 months and my dark spots have faded. It’s part of a skincare routine."

— Patricia S. (5/5)

I love the product, it

"I love the product, it lighten up my skin ,fine wrinkles disappeared, moisturizes my skin for the whole day. Highly recommended."

— Susan C. (5/5)

"I have not used this product. I bought it for someone else."

— Cherlyn (3/5)

Anyone else have this issue?

"This was my first application. All I applied to my face before this serum were hyaluronic witch hazel toner pads that I just wiped my face with. That’s it. Then when I applied this serum and I started to rub it in, it started to pill. Heavily. Is it supposed to do that? I was trying to apply this and then eventually add my makeup on my face but now worried it’s gonna pull"

— Mal (3/5)

I have only been using

"I have only been using this for a few weeks and have noticed improvements. I love the way it makes my skin look, hydrated and glowing. A little goes a long way. I layer this product on top of the snail mucin."

— Kelley T. (5/5)

Love this product, it really

"Love this product, it really helps keep my acne under control."

— Yazmin C. (5/5)

This is the most powerful

"This is the most powerful niacinimide serum that I’ve used. It gives that glass skin perfection and makes skin look poreless"

— Michelle G. (5/5)

Its good

"Its good"

— Puja A. (5/5)