OK, there is some truth that sleeping with wet hair isn’t the best way to treat hair. The main reason is that the structural integrity of hair weakens when wet, as cuticles naturally lift up when damp, making the hair more elastic, vulnerable, and prone to breakage. Along with that, there are also scalp concerns associated with sleeping with wet hair—as well as simple aesthetic issues.
“Simply put, hair is at its most vulnerable when wet. Sleeping with wet hair can lead to a host of problems for the scalp: unwanted bacteria, fungal infections, skin irritation, itchiness, dryness, redness, and dandruff,” says hairstylist Miko Branch, co-founder of hair care brand Miss Jessie’s Original. “Also, it can damage the hair cuticle, flatten strands, create an unpleasant hair odor (dampness mixed with natural sweat) and leave you with a matted mess of hair.”
Essentially, the most concerning part about sleeping with your hair wet is that it leaves your hair open to damage, tangling, and splits. So if you are someone who perpetually wakes up to knotted, frizzy, and brittle strands, you may want to quit the night shower. And, too, if you are also someone who suffers from scalp concerns like irritation, flakes, and inflammation, you may also need to reevaluate your habit, as it may be the root cause you hadn’t considered yet.
So sounds, ahem, not great. However, most stylists will also agree that there’s certainly some nuance here. “I think something like this is case by case,” says hairstylist Marcus Frances, an ambassador for hair care brand Better Natured. “Yes, when the hair is damp it usually is more fragile so the friction against your pillow can, not always, further weaken the hair causing split ends or breakage. But this tends to be a bigger concern for those who already have really damaged hair. If that’s not you, you’ll probably find you don’t run into these issues.”
Basically: if you find that it’s not messing with your scalp, style, or strands, you can continue as normal, just with a few of these caveats.