The Niacinamide 15 Serum — Reddit Reviews
by COSRX
Updated October 10, 2026
15% niacinamide serum for oil control and smoother-looking pores; fast-absorbing.
What the community says
Redditors reach for this as a lightweight niacinamide step for oil, pores, and post-acne marks. It sinks in fast and layers easily, but 15% is strong enough that some people prefer using it at night or avoid it if they’re reactive.
What this means for you
What people love
- 15% niacinamide for oil and pores
- Fast-absorbing, lightweight finish
- Can calm redness and inflammation
Watch out for
Product details
Skin type data limited
What the science says
Acne
Some evidence
Niacinamide: 6 studies tested it on its own. See all 17 studies
What the studies found
Hyperpigmentation
Some evidence
Niacinamide: 5 studies tested it on its own. See all 20 studies
Skin Barrier
Not proven yet
Few or mixed studies. This claim isn't established.
Niacinamide: 1 study tested it on its own. See all 17 studies
Research context, not treatment advice. Studies are about the ingredient, not necessarily this exact product.
Real Reddit threads — 10 mentions across 7 threads
COSRX The Niacinamide 15 Serum on Reddit, in one place — 7 threads from r/koreanskincare, r/AsianBeauty and 1 more, summarized.
“Niacinimide serum (night only)”
Positive
“I am currently using a COSRX regimen and it’s completely transformed my skin.”
Positive
“I have almost no visible acne and my skin feels so smooth, tight, but hydrated.”
Positive
“After I wash my face, I put a tiny bit of Cosrx Niacinamide & Zinc Serum.”
Positive
“It cuts down the oil that messes up your makeup later.”
Positive
“Thai here 👋 After I wash my face, I put a tiny bit of Cosrx Niacinamide & Zinc Serum.”
Positive
“It burned my skin but my skin tolerates Cosrx niacinamide 15.”
Mentioned
“So not sure about the formulation.”
Mentioned
“Cosrx niacinamide 15”
Mentioned
“COSRX The Niacinamide 15 Serum”
Positive
“The serum is what made a big difference in acne and appearance of pores for me”
Positive
“but every step is important”
Positive
“Recommended: COSRX 15% Niacinamide Face Serum”
Positive
“It absorbs fast and feels lightweight.”
Positive
“I can use it every day with no problems.”
Positive
“COSRX 15% Niacinamide Face Serum (websites I mentioned, Amazon and TJ Maxx/Marshalls).”
Mentioned
“There are more expensive ones you can try if you're not feeling the DT.”
Mentioned
“A lot of people who describe their skin the way you describe yours experience benefits from a niacinamide serum.”
Mentioned
