A Pharmacist Explains: Sleeping on Your Side or Stomach Leaves "Sleep Wrinkles" - Plus Three More Habits That Age Your Face

You can have a hundred-euro serum on the shelf and still press the same half of your face into the pillow for seven or eight hours every night. Pharmacist Amanda Isabel Gonçalves, a dermopharmacy expert at Spanish dermocosmetics company Planet Skin, singles out four everyday habits that leave marks on our faces without us even noticing.

1. Sleeping on your side or stomach. "When we sleep on our side or stomach, some areas of the face stay compressed for hours and so-called sleep wrinkles can appear," she explains. The pressure and distortion of the skin in those positions are why lines are sometimes deeper on one side of the face than the other. Her advice isn't to change position overnight: "More than obsessing over changing position, what matters is taking special care of hydration and not forgetting the neck, an area we often leave out of our routine."

2. Mouth breathing. If you don't have a cold but still breathe through your mouth all the time, it shows on your face. The muscles in the lower face stay more relaxed, so over time "the jaw can look less defined, the nasolabial folds more pronounced and the area under the chin more visible". Even more important is finding the cause: "If mouth breathing is frequent, it's a good idea to see what's behind it, as it may be linked to difficulty breathing through the nose."

3. Looking down at your phone. So-called "tech neck" comes from long hours with the head bowed and the neck bent. "That constant tension can make wrinkles in that area more pronounced and the neck lose definition." Here the advice, naturally, includes a 29.90-euro neck cream sold by Planet Skin, where the expert works. But the real part of the advice is free: lift the phone to eye level, straighten your posture whenever you remember, and extend your face routine down to your neck and décolletage.

4. Sleeping in make-up. You pay for this with blemishes, less glow and earlier ageing. At night the skin needs to be clean of everything that built up during the day, but not with harsh products. Gonçalves recommends double cleansing, "the best thing Korean cosmetics left us": "The first step removes the oiliest and most stubborn residue, and the second finishes cleaning the skin. It's not about cleansing harder, but better and more gently on the skin's protective barrier."

Of the four habits, three cost exactly nothing: a raised phone, nose instead of mouth, and five minutes in front of the mirror before bed. The industry rarely advertises advice that doesn't come in a jar. Which of us is going to bed tonight without taking off our make-up "just this once"?