Niacinamide (Vitamin B3): what the evidence says
The claim: Niacinamide refines pores, evens tone and supports the barrier; the 'never mix with vitamin C' rule is a myth.
Strong evidence
What the research actually shows
Niacinamide is one of the best-supported cosmetic actives, with reasonable evidence at roughly 2-5% for helping even the look of tone, soften the appearance of enlarged pores, support sebum balance and reinforce the moisture barrier. Higher concentrations raise irritation risk without clear added benefit for most people. The old warning against pairing it with vitamin C is essentially a debunked myth based on outdated lab conditions; in modern formulations they coexist fine. Well tolerated by most skin types.
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🙋 People also ask
Can you use vitamin C and niacinamide together?
Yes, current understanding is that vitamin C and niacinamide can be used together safely, and many Korean formulas combine them. The old warning that they cancel out is largely outdated. If your skin is sensitive, you can still apply them at different times of day to be cautious.
What does niacinamide do?
Niacinamide is a form of vitamin B3 widely used in Korean skincare to help brighten the look of dullness, refine the appearance of pores and support the skin barrier. It's gentle, well tolerated by most skin types and pairs easily with many other ingredients.
Can I use vitamin C and retinol together?
Not in the same layer, but easily in the same routine — vitamin C in the morning, retinol at night. That split suits both: vitamin C partners with sunscreen, and retinoids are degraded by light.
✍️ Written & reviewed by the KoreaPlus Editorial team — dermatologist-informed, cosmetic-science researched & source-cited. Last reviewed: 2026-08-23.
General educational information using cosmetic structure-function wording — not medical advice. Always patch-test new actives. © KoreaPlus.