We all have our favorite sleeping positions, whether you’re a fan of the fetal position, one leg out of the covers or maybe you’re a stomach sleeper.

But according to these experts you should always avoid sleeping on your side — it could be giving you wrinkles.

The pros at Best Life explained that this sleeping position is the worst if you want to look youthful, since your face is pressed against the fabric of your pillow for prolonged periods of time.

Beth Goldstein, MD said: “Sleeping on your side can lead to some wrinkling.”

However, it’s “more obvious on more lax skin, which is why you’ll see it on an adult’s chest but rarely on a child’s,” According to Deanne Mraz Robinson, MD, who spoke to Allure.

Simply put, when your face is smashed up against your pillow for hours at a time you face is more likely to crease in those same places.

The same goes for lines on your chest, which can appear if you sleep on your side.

However, sleeping on your stomach might be just as bad according to the pros.

“Wrinkles from sleeping on your stomach are thought to be due to repeated stress on the skin,” explains Goldstein.

“When you’re young and have great collagen and supportive skin elements, they resolve shortly after awakening—but over time, the persistent stretching can indeed lead to sleep wrinkles,” she added.

Sleeping on your back is the best option not only for waking up feeling refreshed, but for your skin.

If you’re prone to tossing and turning during the night you could try putting pillows on either side of your face and body to prevent moving onto your side as you sleep.

That said, while not having wrinkles might be nice, waking up feeling well rested is nicer.

Goldstein explained that if you’re unable to sleep on your back “it may not be worth the trade-off.”

After all, “good sleepers look younger and have more hydrated skin,” she added, meaning that the best way to sleep is however you feel most comfortable.

This story originally appeared on The Sun and was reproduced here with permission.