Many people believe that skin dehydrates only during the day due to external aggressions.
However, skin also loses moisture during sleep.
This natural phenomenon, called insensible water loss (IWL) or transepidermal water loss, occurs when water present on the skin's surface gradually evaporates throughout the night.
For people with dry or dehydrated skin, this loss of hydration can lead to a feeling of tightness, a dull complexion, or less comfortable skin upon waking.
This is one of the reasons why night care products have become increasingly popular.
By helping to maintain hydration throughout the night, night care products aim to leave skin softer, more comfortable, and visibly fresher upon waking.