COSRX The Niacinamide 15 Serum 20ml dropper bottle with a clinical, minimalist design.

Clear, watery texture of COSRX Niacinamide 15 serum being applied to the face.

A before-and-after comparison of a cheek with post-acne marks fading after using COSRX 15% Niacinamide.

Close-up of Zinc PCA and Allantoin ingredients featured in the COSRX Niacinamide 15 formula and Texture.

Close-up of Zinc PCA and Allantoin ingredients featured in the COSRX Niacinamide 15 formula.

Infographic showing the reduction of sebum and blackheads after 4 weeks of Niacinamide 15 use.

COSRX / Serums

COSRX The Niacinamide 15 Serum

$29.95 $38.00

Take control of your complexion with COSRX The Niacinamide 15 Serum. This potent, non-sticky formula combines a maximum concentration of Niacinamide with Zinc PCA and Acetyl Glucosamine to provide a triple-threat against acne. It works by regulating the "grease" at the source, soothing red, angry pimples, and smoothing out rough skin texture. Despite its high potency, the addition of Allantoin ensures your skin stays calm and resilient. It’s a clinical-grade polisher that delivers a clearer, more refined look in as little as four weeks.

Sebum Suppression
Pore Refiner
Complexion Brightener
Acne Recovery and Texture Smoothing

Option: 20 ml

What It Is

A high-strength, 15% Niacinamide serum engineered to aggressively control sebum, minimize enlarged pores, and fade post-acne hyperpigmentation.

Why It's Different

The "Secret Sauce" is the Synergistic Ratio of 15% Niacinamide + NAG. While Niacinamide is a superstar on its own, adding N-Acetylglucosamine (NAG) creates a biological powerhouse that is significantly more effective at inhibiting melanin than Niacinamide alone. This makes it a specialist in "erasing" the ghost of old pimples. Additionally, the liquid, water-like texture is specifically designed not to pill under makeup or heavy moisturizers.

Who it's For

Ideally for oily and combination skin types prone to recurring breakouts, congestion, and persistent dark spots (PIH/PIE).

Ingredients

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

How to Use

After cleansing and toning, apply a few drops to problem areas or entire face.
Pat gently to help absorption.
Follow with moisturizer. Use SPF during daytime.

*Patch test recommended before facial use.

Bonza Nourishing

Skin-Beautifying Ingredients

Niacinamide

Improves skin texture, reduces redness and inflammation, and minimizes pores

Allantoin

Calms irritated skin and helps reduce signs of sensitivity

Citric Acid (AHA)

Exfoliates the skin, promoting a brighter and more even complexion

Zinc PCA

Helps to balance sebum

N-Acetylglucosamine (NAG)

Gentle care for built-up sebum

COSRX Pure Fit Cica Clear Cleansing Oil

$28.00

View Product

2

COSRX Advanced Snail Mucin Gel Cleanser

$29.95

View Product

3

COSRX AHA/BHA Clarifying Treatment Toner

$24.99

View Product

4

COSRX The Niacinamide 15 Serum

$29.95

View Product

5

COSRX Advanced Snail 92 All in One Cream

$19.95

View Product

Clinical Assessment: COSRX The Niacinamide 15 Serum

In clinical trials conducted over 4 weeks on acne-prone skin:
50% reduction in whiteheads and pore-clogging debris.
48% improvement in overall skin oiliness and shine.
42% reduction in blackheads.
24% reduction in visible skin redness and inflammation.
Proven Improvement in skin clarity and tone evenness within 2–4 weeks of consistent use.

Frequently asked questions

Is 15% Niacinamide too strong for me?

If you have very sensitive or dry skin, start by using it 2–3 times a week. For oily/acne-prone skin, it is typically well-tolerated daily.

Can I use this with Vitamin C?

It is best to alternate: use Vitamin C in the morning and Niacinamide 15 at night, or vice versa, to avoid potential flushing or irritation.

Does it help with "Fungal Acne"?

Yes, the formula is oil-free and considered fungal-acne safe.

Should I use this before or after the Snail Mucin?

Apply this serum first on clean, toned skin to ensure the actives penetrate deeply, then follow with Snail Mucin to soothe.

How long does a bottle last?

Since it's a 20ml high-concentration treatment, you only need 2–3 drops. One bottle typically lasts 2 months.

See LashViva in Action: Transform Your Lashes Today!

Discover the secret to stunning, natural lashes with LashViva Eyelash Serum. Watch our quick video to see real results and learn how this powerful serum can elevate your beauty routine. Click to explore and enhance your lash game now!

Shop Now

Real Results: LashViva Transformations Unveiled!

See how everyday users achieve longer, fuller lashes and discover how you can too. Click to explore and be inspired by real transformations!

Shop Now

Experience Deep Hydration: Hyaluronic Serum Revealed!

Explore authentic user experiences with Eastern Curlew's Hyaluronic Serum. Watch how real people achieve deeply hydrated, luminous skin. Click to learn more and start your journey to glowing skin!

Shop Now

Timeless Beauty: Experience YouthBloomer Elegance!

Transform your skincare routine with the YouthBloomer Pure Elegance Set. Our video highlights the set's nourishing and revitalizing effects, perfect for achieving a youthful glow. Click to learn more and indulge in elegance!

Shop Now

See LashViva in Action: Transform Your Lashes Today!

Discover the secret to stunning, natural lashes with LashViva Eyelash Serum. Watch our quick video to see real results and learn how this powerful serum can elevate your beauty routine. Click to explore and enhance your lash game now!

Shop Now

Real Results: LashViva Transformations Unveiled!

See how everyday users achieve longer, fuller lashes and discover how you can too. Click to explore and be inspired by real transformations!

Shop Now

Experience Deep Hydration: Hyaluronic Serum Revealed!

Explore authentic user experiences with Eastern Curlew's Hyaluronic Serum. Watch how real people achieve deeply hydrated, luminous skin. Click to learn more and start your journey to glowing skin!

Shop Now

Timeless Beauty: Experience YouthBloomer Elegance!

Transform your skincare routine with the YouthBloomer Pure Elegance Set. Our video highlights the set's nourishing and revitalizing effects, perfect for achieving a youthful glow. Click to learn more and indulge in elegance!

Shop Now

Your Order

COSRX The Niacinamide 15 Serum