Verdict: True
Unfortunately, this popular beauty myth is actually true...
Sleeping on your side and pressing your face against a cotton pillow, or any other surface for that matter, can cause 'sleep lines'. Sleep lines aren't the worst problem in the world however, over time, sleep lines can result in deep, permanent wrinkles.
The best way to prevent sleep lines is to sleep on your back, however training yourself to do this can be tricky and frustrating. So, if sleep lines do concern you, I would recommend investing in a silk pillowcase. A silk pillowcase not only prevents sleep lines, it maintains clean and healthy skin and hair and it feels amazing!