Niacinamide Is Already in Your Moisturizer—Do You Need a Separate Serum?
Disclosure: This is a sponsored article developed in collaboration with Skin Centrick. You find a niacinamide serum you want to try, then notice the same ingredient in your moisturizer. Are you doubling up or could the serum still add something useful? A separate serum is optional. Its value depends on the formula, what you want…