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Niacinamide (Vitamin B3): what the evidence says

Q: Is Niacinamide (Vitamin B3) backed by science?

Strong evidence. 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 The old warning against pairing it with vitamin C is essentially a debunked myth based on outdated lab conditions; in modern formulations they coexist fine.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.

⚡ Quick answer: Niacinamide refines pores, evens tone and supports the barrier; the 'never mix with vitamin C' rule is a myth. — Evidence grade: Strong. 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 The old warning against pairing it with vitamin C is essentially a debunked myth based on outdated lab conditions; in modern formulations they coexist fine.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.

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 The old warning against pairing it with vitamin C is essentially a debunked myth based on outdated lab conditions; in modern formulations they coexist fine.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.

Sources

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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 The old warning that they cancel out is largely outdated.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.

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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.

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✍️ Written & reviewed by the KoreaPlus Editorial team — dermatologist-informed, cosmetic-science researched & source-cited. Last reviewed 2026-06-21.

General educational information using cosmetic structure-function wording — not medical advice. Always patch-test new actives. © KoreaPlus.