Silicone often gets blamed for clogging pores, but its bad reputation may not be entirely deserved, according to Rouleau. Most often used to give skin care and makeup slip and glide, silicone (and its slew of variants, including dimethicone and cyclomethicone) sits on top of the skin, and in and of itself isn't an issue. The problem is that silicone can increase the penetration of other ingredients, which means if you're using a product that contains both silicone and a high concentration of one of the aforementioned culprits, the silicone may be upping its pore-clogging potential, explains Rouleau. Her advice? If you suspect a silicone-containing product is breaking you out, ditch it, but you don't necessarily have to rule out silicone entirely.