We’ve all done it a time or two. You stumble home from a late night feeling too tired to indulge in a skin care routine, so you simply fall into bed wearing a face full of make-up.

Just don’t make a habit of it if you don’t want to traumatize your skin. Cosmetic dermatologist Dr. Paul Frank will tell you that sleeping with your make-up on is a good way to ruin your skin.

That’s what he had to say to Daily Mail writer Anna Purgslove, who decided to go off her skin care regimen for 30 days. In fact, the experiment aged her skin by 10 years, a fact which came to light after her skin was examined beneath a special 3D camera capable of tracing every clogged pore and wrinkle.

Sadly for Anna, the experiment may have lasting consequences for her face. If you don’t wash the make-up off your face your skin won’t be able to breathe. Skin can’t renew or heal itself under these conditions. The make-up can also clog your pores, causing acne.

“Mineral make-up,” which is supposed to be healthier, is no better in this regard. It still blocks your pores and prevents your skin from breathing. It may be softer on your skin while you wear it, but you don’t want to leave it on your face overnight.

So remember to wash your face every night. Clean off all of your make-up, and then treat your skin with a good moisturizer. It only takes a few minutes, and your complexion will thank you!