We paint, contour, and highlight our faces with makeup brushes every day, but we can’t always say the same thing about how frequently we’re cleaning those brushes. Giving them a thorough washing every month or so is not enough. (Shocker.) According to dermatologists and makeup artists, we should be sudsing up our tools far more often in order to prevent bacteria buildup, which can lead to breakouts.

How often should you clean your makeup brushes?

Most dermatologists will tell you to soak your tools, especially foundation and concealer brushes, once a week — minimum — to prevent product buildup. Because these brushes are used on your face, the cleaner they are the better, Frequent cleansing don’t just help keep your skin cleaner. Cleansing your makeup brushes regularly can extend the life of the bristles and make for better product application. Brush hairs and sponges are porous, so they hold onto oils, debris, and bacteria, Dirty brushes can add to improper application and blending of foundation and concealer.