Niacinamide Serum — Reddit Reviews
Updated October 8, 2026
5% niacinamide serum for brightening and pore refinement; can sting reactive skin.
What the community says
A simple niacinamide serum that people use for brightening, fading marks, and keeping pores looking tighter. Redditors say it layers easily, but a chunk of users get redness, dryness, or breakout-y irritation with daily use.
What this means for you
Backed by 18 threads from r/koreanskincare, r/SkincareAddiction and 4 more.
Read the threads ↓What people love
- Brightening step with pore-refining feedback
- Layers cleanly in AM or PM
- 5% niacinamide keeps the formula simple
Watch out for
- Daily use can trigger redness and dryness
- Niacinamide-sensitive skin may break out
- Too much niacinamide seems to backfire for some
Product details
Where to buy
What the science says
Acne
Some evidence
Niacinamide: 6 studies tested it on its own. See all 17 studies
Hyperpigmentation
Some evidence
Niacinamide: 5 studies tested it on its own. See all 24 studies
What the studies found
- All 5 studies that tested it on its own found it helped fade dark spots
- Niacinamide 5% faded dark spots better than a placebo in studies of facial patches
- Used with salicylic acid peels, it improved how dark and widespread the patches were more than peels alone
- A niacinamide mix faded dark spots better than niacinamide alone in one study
- One study found the fading effect reversed after stopping
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 — 32 mentions across 18 threads
Good Molecules Niacinamide Serum on Reddit, in one place — 18 threads from r/koreanskincare, r/SkincareAddiction and 4 more, summarized.
“Good Molecules”
Positive
“Niacinamide Serum and Gentle Retinol Cream - only using them at nightime.”
Positive
“Perfect combo for me.”
Positive
“AM: Cerave foaming cleanser, niacinamide serum (Good Molecules), azelaic acid, Cetaphil 35spf moisturizer”
Cautionary
“As a side note, niacinamide twice a day isn't a good idea, especially when you're using something drying like tret.”
Cautionary
“Niacinamide breaks me out horribly”
Cautionary
“I pair that with my Good Molecules Niacinamide face serum”
Positive
“and The Ordinary Azelaic Acid Suspension 10% with some korean moisturizer.”
Positive
“It's been a game changer.”
Positive
“I started using Good Molecules 10% niacinamide serum a couple weeks ago”
Positive
“I'm pleasantly surprised with the improvements I'm seeing already with reduction in pore size across my cheeks and nose”
Positive
“I started off just using it in the morning but am now using it every morning and evening”
Positive
“the one i currently like is the good molecules niacinamide serum”
Positive
“it react really well! i have both sensitive and oily skin”
Positive
“niacinamide helps oiliness too”
Positive
“My daughter uses Good Molecules niacinamide serum”
Positive
“snail essence twice a day”
Positive
“Her skin is so glowy people comment about it”
Positive
