Why a Derm Says You Should Be Changing Your Pillowcases Every Couple of Days

While there’s hardly a better feeling than laying your head down on a fresh, clean pillowcase at the end of the day, changing your bedding is a process. Once you get past the part where you’re trying to figure out how to clean pillows, or your sheets get tangled up in the dryer and don’t dry all the way, there’s the whole rigamarole of figuring out which are the long sides of the fitted sheet. My personal hell, however, is getting the duvet back into its cover. And if you think washing your sheets once per week—which board-certified dermatologist Hadley King, MD, says is the frequency recommended by the American Academy of Dermatology—is aggressive, wait until you hear how often to wash pillowcases.

*Drumroll* Dr. King says you should be swapping them out around two to three times per week. “When you get into bed, you contaminate your bed linens with dead skin cells (about 50 million per day), sweat, makeup, lotions, hair, and anything else you’ve picked up during the day, from pollen and pet dander to fungal mold and dirt particles to bacteria and viral particles as well,” Dr. King says. “Dead skin cells and sweat provide food for dust mites, attracting them to your bed and helping them multiply.” (Aside: ewwwww.) After the dust mites feed on all the nasty stuff you brought into your bed, they poop, which is both gross and exacerbating to allergies and asthma.

Your sweat and oils are also a breeding ground for bacteria and yeast, a cocktail of two things that are low on the list of “things I want to put my face into.” This increases the risk for skin irritation and infection, and can also contribute to breakouts if you have acne-prone skin, says Dr. Hadley. The absolute longest she would go without changing her pillowcases would be a week—but that’s only if her face, skin, and hair were cleansed every night before bed, and she wasn’t experiencing allergies, skin infections, or skin inflammations.

TLDR: Go change your pillowcases right now.