A high-strength serum with 15% niacinamide—a vitamin B3 derivative that helps regulate oil, fade dark spots, and refine skin texture. This lightweight, watery formula absorbs quickly without residue, making it easy to layer into your morning or evening routine.
Who is This For?
Suitable for all skin types, but especially helpful if you're dealing with excess oil, visible pores, or post-breakout marks. Works well for anyone wanting a more balanced, even-toned complexion.
Key Benefits
Helps control oil and shine throughout the day
Fades dark spots and post-acne marks over time
Minimizes the look of enlarged pores
Calms irritation and supports skin recovery
Key Ingredients
Niacinamide (15%) — Regulates oil, strengthens the skin barrier, and helps even out skin tone
Zinc PCA — Controls sebum and offers antibacterial support to help keep breakouts in check
N-Acetylglucosamine (NAG) — Boosts niacinamide's brightening effects by helping to reduce excess melanin
FAQs
Q: Can I use Cosrx Niacinamide 15 Serum with vitamin C?
A: It is recommended to use vitamin C and high-concentration niacinamide in separate routines (one in AM, one in PM) rather than layering them together, as combining them may reduce efficacy or cause flushing in some individuals.
Q: Is this serum suitable for sensitive skin?
A: The 15% niacinamide concentration is considered high; those with sensitive skin should patch test first and may want to start with every other day application to assess tolerance.
Q: Can I use this serum around my eyes?
A: Yes, the serum can be applied to the under-eye area to address dark spots, but avoid direct contact with the eyes.
Q: Do I need sunscreen when using this serum?
A: Yes, applying SPF 30 or higher during daytime use is recommended, as niacinamide can increase skin's sensitivity and protecting against UV exposure supports the serum's brightening benefits.
Q: How long until I see results?
A: Most users notice improvements in oil control within 1-2 weeks, while fading dark spots and refining texture typically takes 4-8 weeks of consistent use.
Q: When should I apply this in my skincare routine?
A: Apply after cleansing and toning, but before heavier creams or oils; the lightweight formula absorbs quickly and layers well under moisturizer and sunscreen.
Q: Who should avoid using this serum?
A: Those with known niacinamide sensitivity or anyone currently experiencing compromised skin (severe irritation, open wounds, or active eczema flares) should skip this product or consult a dermatologist first.
How to Use
Cleanse your face thoroughly and pat dry. Apply 2-3 drops of serum onto your fingertips. Gently massage the serum into the skin, starting from the center of the face and working outward. Allow the serum to absorb fully before applying the next product. Follow with moisturizer. For daytime use, apply SPF 30 or higher sunscreen as the final step. Can be applied to the under-eye area; avoid direct contact with eyes.
Very high quality packaging and ingredients. Application is simple, just a dropper. The serum is slightly thicker than the hyaluronic serum, but disappears into the skin and works wonders.
B
Beverly W.
I love the COSRX skin
I love the COSRX skin care product line! My skin is on the drier side but still very sensitive. It's been very difficult to find products that keep my face moisturized without breaking out. So many things, even very expensive and quality products, have petrolatum and shea butter in them. Both of them cause breakouts for me. The Niaacinamide 15 is keeping my skin looking radiant. I have bought sever other products and my skin is moisturized and white heads are vanishing.
S
Sandra M.
Everyday skin need
I love niacinamide serums, I have mature skin, normal to oily (depends on the season) and this serum is excellent. My skin can get red and inflamed easily by the simplest products but my skin loved this. I use it daily and will continue to purchase. I recently had a reaction to the ordinarys products and I learned about Cosrx last month.
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Lacy P.
Great!
Great!
M
Madeleine B.
I am astonished at how
I am astonished at how well it works on keeping sebum levels down throughout the course of a busy day on my very sensitive skin.
M
Mila
Niacinamide
I'm excited with this product! I have oil skin and niacinamide really help me to control sebum.
J
Janice P.
Excellent product
Excellent product
R
Robin G.
I have acne rosacea and
I have acne rosacea and this product really has helped my skin
A
Adedayo A.
It's a wonder, by reducing
It's a wonder, by reducing acne residue, it gives me a blend of smooth skin, you should also try it
N
Nathan P.
Good simple serum
Good simple serum
A
Austen G.
Not too harsh on my
Not too harsh on my face and a great addition to my skincare routine. This is actually my second purchase of this product. I use it once a day and the bottle lasted me about 4 months.
M
Melody B.
Amazing!
Amazing!
A
Abisoye L.
good
good
a
ashley r.
This product is light and
This product is light and does wonders for my sensitive skin
D
Danielle M.
Feel nice going on the
Feel nice going on the skin. No scent which I like.
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shiela N.
I was scared of using
I was scared of using this order because usually niacinamide serums feeel like fire on my sling but I think the measured the ingredients correctly as well as not having it flavor one skin tone to the other. So it when I apply the residue it moustirizes my sling although I still feel some burning like putting spirit on a wound
T
Tori M.
I really like this serum.
I really like this serum. I ordered a couple other products based on the quiz so I'm not quite sure what exactly is making my skin look nice or if it's a combination of all of it but my skin is definitely looking brighter and less dull!
J
Jazmyn R.
Great
Love it
E
Erin S.
Great addition to my skincare
Great addition to my skincare routine. Works as described.
L
Lydia H.
Great serum!
So far this product is really great! I like how light weight it feels onto my skin. It also absorbs super fast!
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Dyana N.
Great Serum
At 53, I have some wrinkles and still struggle with enlarged pores and blackheads. After cleansing, I use CosRX's AHA/BHA toner, follwed by their snail mucin, this, and their vitamin C serum. Never thought I'd use that many products in the morning, but my skin looks better after less than 2 weeks and feels very soft.
k
k.r.
Interesting serum
I was looking for a new niacinamide serum to replace the one I’ve been using for ever. However, I gave this one 4 stars as it was a bit harsh on my sensitive skin. I don’t use it much because of this, but I would like to start using it more
H
HW
First time serum
I started to get hormonal acne out of the blue about a year ago. I'm never used a serum before and nothing was helping, so I thought I'm give this one a try since I heard great things about niacinamide. I still have some breakouts here and there, but this has helped immensely in calming down my skin and getting my acne under control!
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Li C.
It's great for the first
It's great for the first time to use this product and I'm very happy to use it!
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sam z.
wawee
for so long i thought i had some allergy with niacinmide because the aprilskin one would do the opposite for me and it worsened my handful of pimples to a severe acne, but i switched to this one for giggles and lo and behold i went from severe acne to a clear face. plot twist of 2023
C
Claudia M.
I love the texture of
I love the texture of the Serum, I use in my daily routine of skincare. This have a really light weight.
D
Dana
Love this
I have bumpy combo skin with fine lines and acne that pops up too often. This serum has done a 180 for my skin. It's so much smoother and exfoliated without being irritated, and I haven't seen new acne since I started using it. My pores have shrunk too and there is much less oil throughout the day.
S
Sarah W.
Really Helpful
I got this to combat acne scars, hyperpigmentation, and larger pores on my cheeks.
After I started using it I have already noticed my skin feeling softer and more plump. I know that over time my scars will diminish and I'm really happy that this is formulated to work on sensitive skin, it is incredibly effective.
J
Jinda R.
Great stuff
Every since my favorite YouTuber recommended this brand I've been in love. Such affordable quality products that work!
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Mia M.
Hydrating
Hydrating
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Loveangie
Stops nose buildup
I received this product for free from influenster in exchange for my honest review. I've been using this more more than a month I have seen a drastic change in my nose which usually gets a lot of buildup. I've been using this in combination with the vitamin c serum and both have tremendously transformed my skin. I have no pimples and my skin is glowing, will repurchase this and keep as a staple.
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Michelle
Niacinamide serum
I received this product in exchange for my honest review compliments of Influenster and Cosrx. And I'm so glad that I got a chance to try it out. I'm very big on skincare and want to do my best to help minimize breakouts. I wouldn't say I have too much trouble with acne, but I definitely have a couple breakouts every month along with some general congestion. But I believe this has been helping me in terms of oil control and exfoliation. It's been great for my combination skin.
A
Aisha
Definitely buying more
I'm definitely buying this, I loved it. Thanks to pcos I have some scarring and texture from over waxing on the bottom of my face, chin and neck. This helped a lot with it, my skin felt and looked smoother. It stung a little this first two times I used it but no problems or irritation.
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