@ahkeng1965: #olay #olaythailand #olaypartner #creatorsearchinsight #whiteningcream The combination of niacinamide and retinol (retindol is likely a typo for retinol) is highly effective, but their roles differ between day and night. Neither is strictly “essential” for everyone, but together they address multiple signs of aging, pigmentation, and barrier health. For Night Moisturizers: Essential Synergy At night, skin enters repair mode. Retinol, a vitamin A derivative, is the star here. It speeds up cell turnover, boosts collagen, and unclogs pores. However, retinol can cause irritation, redness, and barrier disruption—especially when starting out. Niacinamide (vitamin B3) is the perfect partner. It strengthens the skin barrier, calms inflammation, and reduces the stinging or peeling retinol may cause. Additionally, niacinamide supports ceramide production, counteracting retinol-induced dryness. Using both in a night moisturizer maximizes anti-aging benefits while minimizing side effects. Retinol is also photosensitive, so it degrades in sunlight—making night application essential. For Day Moisturizers: Protective, Not Essential Niacinamide shines during the day because it is photostable and offers antioxidant protection against UV and pollution. It also regulates oil, minimizes pores, and improves uneven tone. However, retinol should generally not be in a day moisturizer because UV light breaks it down, reducing efficacy and potentially increasing skin sensitivity to sunburn. That said, some modern “day creams” include low-dose retinol only if paired with high-SPF sunscreen—but this is rare and not recommended for beginners. Niacinamide, by contrast, is perfectly safe and beneficial in day creams. Bottom Line · Night moisturizer: Both are ideal—retinol for repair, niacinamide for barrier support and irritation control. · Day moisturizer: Niacinamide only (essential for protection and oil control). Retinol does not belong in day creams unless used strictly with SPF, and even then, night use is superior. In short, for a night cream, the duo is game-changing. For day cream, prioritize niacinamide plus sunscreen; retinol is unnecessary and counterproductive. 为什么烟酰胺和视黄醇对日霜或晚霜很关键？烟酰胺和视黄醇的组合功效很强，但它们在白天和夜晚的角色不同。两者对所有人来说都不是“绝对必需”，但一起使用能针对抗老、淡斑和修护屏障。用于晚霜：堪称黄金搭档夜间皮肤进入修复模式。视黄醇（维生素A衍生物）是核心成分：它加速细胞更新、促进胶原蛋白生成、疏通毛孔。但视黄醇可能引起刺激、泛红或脱皮。烟酰胺（维生素B3）能强化皮肤屏障、舒缓炎症、减少视黄醇带来的刺痛感。同时，烟酰胺促进神经酰胺生成，缓解视黄醇引起的干燥。两者结合能最大化抗老效果并降低副作用。另外，视黄醇遇光易分解，必须夜间使用。用于日霜：烟酰胺有益，视黄醇不推荐烟酰胺在白天表现出色：它性质稳定，能抗紫外线/污染伤害，还能调节油脂、细化毛孔、提亮肤色。但视黄醇不应出现在日霜中，因为紫外线会使其失效，还会增加皮肤晒伤风险。除非日霜搭配高倍防晒且视黄醇浓度极低，但这并不常见，新手尤其要避免。总结 · 晚霜：两者都理想——视黄醇负责修复，烟酰胺负责舒缓屏障并减轻刺激。 · 日霜：只用烟酰胺（防护、控油、提亮），视黄醇没必要且有害。简言之，晚霜中这对组合功效强大；日霜则优先选烟酰胺+防晒霜，视黄醇留在夜晚使用。