The skin on the face is very sensitive and it is the first to be marked by the signs of fatigue. So it's no secret, a good night's sleep helps reduce dark circles, bags under the eyes and even wrinkles. But how is this possible?Sleep promotes the microcirculation of blood, mainly under the eyes. It also allows the release of growth hormones that help the skin to regenerate at night and even heal faster. Inversely, a lack of sleep leads to sagging skin that goes hand in hand with a loss of elasticity of the tissues. Just common sense…Sleepless nightsIt is proven that after sleeping less than 5 hours a night (especially for a woman), the skin takes 30% more time to repair its protective barrier. It is therefore advisable, for a good quality of skin, to sleep between 7 and 9 hours per night. Added to this is the stress hormone, linked to a lack of sleep. This is known as cortisol. When it is produced, it damages the collagen which is naturally present in the skin and lead to unnecessary sebum production. Sebum causes shiny skin and dilated pores... Everything you want to avoid!Check out the video above for more on why getting enough good quality sleep is the only beauty skincare secret you need!