“I need to catch up on my beauty sleep.”

I’m sure we’ve all said it or heard it at one time or another, typically with a hint of sarcasm.

But there’s no joke about it: beauty sleep is real!

Remember: your skin isn’t just some “thing” that keeps all of your insides wrapped up and in place — the skin is the body’s largest organ! And like all organs, the skin is impacted by your overall health and wellbeing. Of course, there are specific aspects of health that particularly impact the skin, and sleep is one of them.

A good night’s sleep is extremely important for skin health.

Sleep is a time of repair and regeneration, for both the body and skin.

The body’s production of human growth hormone increases during sleep. This hormone increases collagen production and is also necessary to repair some of the DNA damage that may have been caused during the day — the DNA of skin cells is impaired by UV rays and environmental pollution, which cause free-radical damage and premature aging. These repairing, regenerative processes are impaired when sleep is interrupted or cut short.

A lack of sleep increases cortisol levels, which impairs collagen synthesis and repair.

Cortisol is a hormone that the body releases when it experiences stress, either physical or emotional. It serves a purpose and is completely healthy in moderation, but causes problems when levels are chronically elevated (like throwing the body’s other hormones out of balance and promoting belly fat!).

Cortisol damages collagen, and impedes its repair and synthesis. It also prevents hyaluronic acid synthesis, which keeps skin hydrated and plump, and thins the top layers of the skin, causing a red and blotchy complexion since the blood vessels beneath the skin are more pronounced.

A lack of sleep promotes systemic inflammation, which wreaks havoc on the skin.

Immune cells called monocytes that make inflammatory chemicals are more active when we are sleep deprived. Like cortisol, inflammation is natural and necessary but causes some significant health problems when in excess.

Inflammation wreaks havoc on the skin, triggering outbreaks of eczema and acne as well as accelerating skin aging. The connection between chronic inflammation and premature aging is so well-known that it’s often referred to as inflamm-aging.

Adequate sleep is necessary for the liver’s natural detoxification process, which is critical for skin health.

Sleep is a time when the liver is particularly active and working to detoxify the body of toxins as well as used and excess hormones. If this process is interrupted or incomplete, it shows on the skin. When the liver cannot properly detox toxins and hormones, the body will try to get rid of them via other detoxification pathways, one of which is the skin. As toxins are expelled through the skin, they can damage cells and cause inflammation (which as we just discussed, aggravates all skin issues). And if excess and used hormones aren’t properly detoxed, the body can experience a hormonal excess which cause adult acne and prematurely age the skin.

So how much beauty sleep do we need?

Since we’re all biologically unique individuals, this varies and depends on the individual. But generally speaking, 6-9 hours seems to be the optimal range.