Niacinamide may enhance the function of your skin’s lipid barrier (a layer of water and oil that protects your skin). This helps lock moisture in and keep pollutants or other potential irritants out, making your skin more hydrated and less sensitive. Niacinamide has been shown to ease inflammation, which can help calm redness due to conditions like acne, rosacea and eczema. It can also soothe irritation caused by strong exfoliants like retinol or glycolic acid that remove dead cells from the surface of your skin.