Skin appears more beautiful, smooth, and plump upon waking in the morning because the reclined position during sleep evenly distributes bodily fluids toward the face, which temporarily fills in fine lines before gravity causes these fluids to drain back down over the course of the day.

noli's read

This observation is based on fascinating biological realities related to gravity and our body's fluid dynamics. An observational clinical study by Tsukahara et al. (published in 2001 in the British Journal of Dermatology) demonstrated that facial skin thickness is significantly higher in the morning than in the afternoon. During the night, the horizontal position allows body fluids (interstitial water) to distribute homogeneously, which slightly and naturally swells facial tissues. Another clinical study by the same author (2004, Archives of Dermatological Research) confirms that forehead and eye-contour fine lines are measurably less deep upon waking thanks to this natural swelling phenomenon. However, this 'plumping' effect is ephemeral because gravity quickly causes these fluids to drain downward as soon as we spend the day standing. The idea of optimal hydration should also be nuanced: research shows that water loss via evaporation is actually higher during the night, making the skin barrier drier upon waking despite the plump appearance.

the sources

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