Aside from SPF, a retinol serum and a good brightening vitamin C product are two other oft-cited elements of a solid skincare strategy. If you’re already using vitamin C, though, it may seem unnecessary to incorporate an additional, seemingly similar, ingredient. Keep reading to find out what they say about using niacinamide and vitamin C together, plus product recommendations for each. “Naturally, vitamin C is found in citrus fruits, berries, and peppers.” But, when it’s used in skincare, vitamin C often goes by another name, L-ascorbic acid. “Vitamin C brightens and boosts collagen, while niacinamide calms irritation and strengthens the skin barrier, making it easier to tolerate vitamin C.” She says that you could use a vitamin C serum in the morning and layer a niacinamide serum on top for a glow-boosting duo that also offers skin protection.