Niacinamide (vitamin B3) at 5% is a water-soluble active used to improve skin barrier function, reduce transepidermal water loss, even skin tone, and regulate sebum. It is well tolerated by most skin types and works through multiple pathways including ceramide synthesis and inhibition of melanosome transfer.
| Reported effect | How often | Notes |
|---|---|---|
| Mild transient flushing or warmth | Uncommon | Usually brief and harmless; more associated with oral niacin than topical niacinamide. |
| Stinging, tingling, or burning | Uncommon | More likely on sensitive or compromised skin or at higher concentrations. |
| Erythema (redness) or irritation | Uncommon | Often resolves with reduced frequency or lower concentration. |
| Contact dermatitis or allergic reaction | Rare | Genuine allergy is uncommon; patch testing can confirm. |
| Acne flare or purging-like reaction | Rare | May relate to other formulation ingredients rather than niacinamide itself. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.