Niacinamide, also called nicotinamide, is a form of vitamin B-3, an essential nutrient. As a skin nutrient, it helps to tighten pores, minimize visibly enlarged pores, improve uneven skin tone, soften fine lines, decrease the look of wrinkles, retexture skin surfaces and diminishes the look of dull skin. It has also shown to be effective in eczema and acne.