You might have noticed that your skin looks plumper and brighter when you wake up in the morning compared to at night. It’s not just that you’ve gotten some rest, and you’re not simply imagining it! Peer-reviewed studies have found that your skin is actually thicker in the morning than at night, and wrinkles are less pronounced in the morning as well.

While there’s no doubt that adequate sleep will make you feel and look less tired, wrinkles can’t heal overnight. So what’s happening?

Gravity and dermal fluid in the morning and evening

The biggest impact is gravity. The deeper layers of your skin, the dermis, consists of cells surrounded by liquid called dermal fluid. Dermal fluid isn’t contained within cells (it’s interstitial fluid), so it can move down slowly between the cells in your skin, under the influence of gravity. During the day as you’re upright, the dermal fluid moves towards your legs, but overnight, when your body is horizontal during sleep, dermal fluid settles back. This swells up your facial skin, reducing the appearance of wrinkles, like pumping water back into a raisin or rehydrating a shriveled, dried sponge.

The effect is similar to how standing around for a long time will cause swollen feet and ankles as fluid pools to the lowest regions of your body.

Facial Movement Throughout the Day

Another possible reason for the changes in wrinkle depth that the authors of the wrinkle study suggest is facial movement. When your facial muscles move, they also shift the overlaying skin. Some wrinkles are caused by these muscle contraction – for example, when Botox is injected into the forehead to paralyse specific muscles, frown lines become less visible. The authors suggest that throughout the day, any wrinkles that momentarily form as you talk, eat, smile, frown etc. will deepen and become more ingrained, just like if you repeatedly crease the same area on a leather shoe or a piece of paper.

Take-Home Messages

If you want to minimise shriveled skin and wrinkles, you should stay in bed for as long as possible and take more naps. Thanks, science!

Further Reading

K Tsukahara, Y Takema, S Moriwaki, T Fujimura & G Imokawa, Dermal fluid translocation is an important determinant of the diurnal variation in human skin thickness, Br J Dermatol 2001, 145, 590-596

K Tsukahara, S Moriwaki, M Hotta, T Fujimura & T Kitahara, A study of diurnal variation in wrinkles on the human face, Arch Dermatol Res 2004, 296, 169-174