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.
COSRX sustainability infographic demonstrating how The Niacinamide 15 Serum’s dropper cap can be easily separated for recycling; highlights eco-friendly packaging and brand’s environmental responsibility in K-beauty formulation.
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.
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.
COSRX sustainability infographic demonstrating how The Niacinamide 15 Serum’s dropper cap can be easily separated for recycling; highlights eco-friendly packaging and brand’s environmental responsibility in K-beauty formulation.
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.

The Niacinamide 15 Serum

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 

$25.00
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Concerns & Benefits
Concern Suitable Key Benefit Key Ingredient
Excess oil & sebum Yes Controls oil & shine Niacinamide 15%
Enlarged pores Yes Refines and minimizes pores Niacinamide + Zinc PCA
Uneven tone & marks Yes Brightens and fades spots Niacinamide + Acetyl Glucosamine
Rough texture Yes Smooths surface Niacinamide + Allantoin
Acne & breakouts Yes Soothes and clears Niacinamide + Zinc PCA
How to Use
  1. After cleansing and toning, apply a few drops to problem areas or entire face.
  2. Pat gently to help absorption.
  3. Follow with moisturizer.
Use SPF during daytime.

    4. *Patch test recommended before facial use.
Product Fact Pack
Info Details
Volume 20mL
Key Ingredients 15% Niacinamide, N-acetylglucosamine, zinc PCA, Allantoin
Clinically Proven Yes (Non-comedogenic tested, Dermatologist tested)
Expiration 36 months from manufacturing or 12 months after opening
Allergens Hypoallergenic tested
Why COSRX?
Feature Niacinamide 15 Typical Serum
Niacinamide Concentration 15% niacinamide + acetyl glucosamine + zinc PCA Usually 5–10%
Skin-Target Test Result Sebum reduced ~50% after 4 weeks Not always tested
Texture Absorbs easily, non-comedogenic Heavy / tacky
Suitable skin types Especially for oily & combination skin. Also suitable for sensitive skin (with Allantoin). Often specified for fewer skin types

Clinically proven to reduce sebum by up to 50% in 4 weeks. Tested by the Dermacosmetic Skin Science Laboratory Co., Ltd.

Ingredient List
Water, Pentylene Glycol, Niacinamide(15%), Butylene Glycol, Acetyl Glucosamine, 1,2-Hexanediol, Zinc PCA, Trehalose, Xanthan Gum, Pullulan, Allantoin, Ethylhexylglycerin, Sodium Phytate, Citric Acid, Tocopherol
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More details Right
ALL-IN-ONE SOLUTION

High-Strength
Total Trouble*
Care

Care for breakouts and address skin concerns with optimized ingredients

*Trouble refers to skin concerns caused by various internal and external factors, such as enlarged pores, excess sebum, uneven texture, and dryness.
Smoothing. Oil-control. Pore-refining. Soothing. Balancing.  
COSRX The Niacinamide 15 Serum bottle with dropper releasing a translucent drop; features 15% niacinamide, Acetyl Glucosamine, and Zinc PCA to target excess oil, uneven tone, and pore congestion with fast-absorbing texture.
Close-up of COSRX The Niacinamide 15 Serum being applied to cheek with a dropper, showing lightweight formula absorbing smoothly into skin; designed for acne-prone and oily skin to reduce sebum and refine enlarged pores.
#TotalTroublecare #ControlSebum

Clearer, Smoother Skin in Just 4 Weeks

Based on a 4-week clinical study conducted by Dermacosmetic Skin Science Laboratory Co., Ltd., Korea.

-50%

whiteheads decreased

-48.07%

oiliness improved

-45.27%

pores reduced

-42.27%

blackheads decreased

-24%

redness reduced

-19.47%

pigmentation improved

All clinical trials were conducted by Dermacosmetic Skin Science Laboratory Co., Ltd. From Aug 27 to Oct 11, 2022, on 20 subjects.

WHO IS IT FOR?

For those who constantly struggle with excess oil, clogged pores, or breakouts and want a serum that restores balance without irritation.

Perfect for anyone looking to smooth rough texture, improve the appearance of pores and support a clearer, more even complexion

Best for those struggling with redness or dark spots left behind by acne, seeking a calmer and more radiant complexion.

Great for those who prefer a gentle, clinically proven formula that helps strengthen the skin barrier without irritation.

Model holding COSRX The Niacinamide 15 Serum near her face, showcasing a hydrated, radiant complexion. The 15% niacinamide formula is clinically tested for acne-prone and oily skin, reducing oiliness, dark spots, and rough texture while supporting barrier health. Clinical trials showed a 42.72% decrease in blackheads and a 50% reduction in whiteheads after 4 weeks of use. Smiling model holding COSRX The Niacinamide 15 Serum and winking, representing inclusive skincare suitable for all skin tones. The formula with 15% niacinamide and Zinc PCA helps balance sebum, minimize pores, and fade acne pigmentation. Clinical testing showed visible melasma and blemishes improved by 14.82% after 2 weeks and 19.47% after 4 weeks. Model applying COSRX The Niacinamide 15 Serum on the cheek with a dropper, showing its gentle texture suitable for sensitive, oily, and acne-prone skin. The formula helps control excess oil, tighten pores, and brighten post-acne marks. Clinical results showed pore count decreased by 45.27% after 4 weeks of consistent use. Model smiling while applying COSRX The Niacinamide 15 Serum onto skin; demonstrates non-sticky, quick-absorbing texture that layers well under moisturizer or sunscreen, suitable for daily acne care and barrier repair routines.

KEY INGREDIENTS

Improves uneven skin tone and pores

15% Niacinamide

Gentle care for built-up sebum

N-Acetylglucosamine (NAG)

Helps to balance sebum

Zinc PCA

Your
Clear Skin
Routine Guide

Step by step routine to get that glowy, clear skin

Start with AC Collection Calming Foam Cleanser to deeply cleanse pores and remove excess oil without stripping the skin.

Step 1 - Cleanse

Follow with the Advanced Snail 96 Mucin Power Essence to replenish hydration and support skin repair.

Step 2 - Prep

Apply The Niacinamide 15 Serum to balance sebum, help prevent breakouts, and refine uneven texture.

Step 3 - Clarify

Finish with Vitamin E Vitalizing Sunscreen SPF 50+ for non sticky protection against UV damage without white cast.

Step 4 - Don't forget to

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FAQ
What makes COSRX The Niacinamide 15 Serum effective for oily and acne-prone skin?

COSRX The Niacinamide 15 Serum contains a 15% concentration of niacinamide combined with Zinc PCA. This formula helps regulate sebum production, minimize the appearance of enlarged pores, and help breakouts care while calming redness. The lightweight, non-sticky texture makes it ideal for oily and congested skin that needs active yet gentle care.

How does niacinamide help control sebum and minimize large pores?

Niacinamide helps support by balancing excess oil production and strengthening the skin barrier, which helps reduce the buildup of sebum inside pores. Over time, this helps pores appear smaller and skin texture become smoother. The addition of Zinc PCA in COSRX’s formula enhances this oil-control effect for visibly clearer skin.

When can I expect to see results from using The Niacinamide 15 Serum?

Clinical tests by the Dermacosmetic Skin Science Laboratory showed visible improvements in 4 weeks, including a 45% decrease in pore size, 48% reduction in oiliness, and improvement in skin tone and blackheads.

Can COSRX The Niacinamide 15 Serum be used with other active ingredients?

It’s best not to use AHA & BHA, Vitamin C, or Retinol at the same time, as they can be too strong when combined. Instead, use them at different times of the day. Hydrating ingredients like Hyaluronic Acid or Peptide Serum, however, are gentle and can be used together for added moisture.

Does the Niacinamide 15 Serum Help with Blemish Scars?

Yes. The high-strength niacinamide and Acetyl Glucosamine combination targets dark spots and uneven tone caused by acne. Clinical data shows a 19% improvement in pigmentation and 15% reduction in blemishes after four weeks, helping restore skin clarity and radiance.

Is COSRX The Niacinamide 15 Serum suitable for sensitive skin?

The formula is clinically proven and proven non-comedogenic, meaning it will not clog pores or trigger breakouts. It’s free from common irritants and formulated to calm redness, making it suitable for both acne-prone and sensitive skin types.

How should I include The Niacinamide 15 Serum in my daily skincare routine?

After cleansing and toning, apply 2–3 drops of the serum evenly across the face. Follow with a moisturizer to lock in hydration. The serum absorbs quickly and layers well under sunscreen or makeup, making it suitable for both morning and nighttime use.

Overall rating: 4.5877275 / 5 from 1043 reviews.

AI Generated Review Summary

This serum is praised for its ability to absorb well, leaving a light residue. Customers appreciate its smooth texture and the noticeable difference it makes to their skin, making it look smoother and more even-toned. It is also effective in reducing pimples and pores, and is non-comedogenic.

Summary topics

  • Absorption: 11%
  • Texture: 6%
  • Effectiveness: 6%
  • Visible Improvement: 9%
  • Pore Refinement: 9%

Review topics: ["pores","feels","skin","works","absorbs","looks","texture","serum","packaging","results","face","concentration","residue","improvement","breakouts","scent","acne","bottle","quality","difference","oil","spots","consistency","niacinamide","weight","glow","fragrance","use","ingredients","formula"].

Review highlights

  • "My skin looks great and I did see a small difference in the size of my pores and the overall texture of my skin!!" — Vanessa C.
  • "Moreover, the pores look smaller and tighter, while the skin feels smooth and soft." — Viruzzzka
  • "This works really well on my skin, doesn’t leave a weird oily finish it gives a nice glow and my skin absorbs it well." — Brittany C.

Reviews

Just added this to my

"Just added this to my routine have been using the clearing pads for years and along with this new product my skin is looking even better. I will continue to buy!"

— Sade K. (5/5)

CosRx is my favorite affordable

"CosRx is my favorite affordable skincare!! This stuff is great - works well for my husbands backne!"

— Paigen J. (5/5)

Love this stuf this stuff.

"Love this stuf this stuff. Keeping it in my rotation at all times is one of the reasons I keep getting other corsrx products(like to meet that free shipping min). Does pill like other brands. Absorbs quickly. When I use it consistently, even my hormonal acne isn't as bad."

— Bethani D. (5/5)

Helps me a lot with

"Helps me a lot with my skin texture reducing the pores."

— Pablo U. (5/5)

The serum is light weight

"The serum is light weight and leaves my skin looking and feeling great. Over time I have noticed that my pores are smaller and I don’t see as many white heads. This is a regular in my routine."

— Kristina C. (5/5)

My skin cannot survive without

"My skin cannot survive without this! Gentle enough for sensitive skin. Help prevent stubborn blemishes and control oil"

— Amira L. (5/5)

I really like this product.

"I really like this product. It's one of the best. It's my third purchase. It leaves my skin beautiful and my pores were dramatically recast. I love the Niacinamide 15"

— Irma P. (5/5)

I'm currently using it. It's

"I'm currently using it. It's been about a week, and it's good."

— Na K. (4/5)

The has no residue and

"The has no residue and provides firmness and control"

— Eva E. (5/5)

I love this product. I

"I love this product. I have struggled with large pores for so long, but this has helped shrink them so significantly. I also have pretty sensitive skin, but this doesn’t irritate my skin at all. My only complaint is that it doesn’t last as long as my other COSRX products, but it honestly feels worth it because it does so much for me."

— Samantha L. (5/5)

Q&A