Makeup brushes don’t expire, but they can lose their bristles and become stiff with use over time, especially if they’re not cared for properly. Aim to clean your brushes at least once per week using a designated brush cleanser but do so gently to avoid damaging the bristles. After washing your brushes and letting them air dry completely, store them somewhere safe and dry, like a designated brush holder or in a cup in your bathroom cabinet (bristle side up). If you’re doing all of that but still feel like your brush isn’t working as well as it should be, it might be time to replace it.