烟酰胺 × 防晒

临床研究显示4%烟酰胺改善色素沉着，与氢醌效果无统计学差异，且副作用更少

Clinical study showed 4% niacinamide improved pigmentation with no statistical difference from hydroquinone, and fewer side effects.

临床研究显示含4%烟酰胺和2%NAG的配方显著减少面部色素沉着，效果优于安慰剂

Clinical study showed formulation with 4% niacinamide and 2% NAG significantly reduced facial hyperpigmentation compared to vehicle.

临床研究显示5%烟酰胺显著减少色素沉着并提亮肤色，体外实验证实抑制黑素体转移

Clinical study showed 5% niacinamide significantly reduced hyperpigmentation and increased skin lightness; in vitro confirmed inhibition of melanosome transfer.

该文研究口服烟酸（而非烟酰胺）对光致癌和光免疫抑制的预防作用，涉及防晒相关机制，但成分和给药方式不同

This study investigated oral niacin (not niacinamide) on photocarcinogenesis and photoimmunosuppression, involving sun protection-related mechanisms, but the ingredient and route differ.