Women need more sleep and studies have recently shown that it is because of the extra work female bodies go through.

Here’s what we know.

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Why do women need more sleep than men? Women experience a longer circadian rhythm than men do and women experience a longer melatonin rhythm than men, according to a study published in the journal PNAS Plus

Patrick Flynn wrote in a social media post on Instagram, “Women have a longer circadian rhythm than men which leads to more sleep for women. Men need 7-8 hours of sleep where women need 8-10 hours which leads to different circadian rhythms. The sleep cycles are similar, but cortisol goes down and melatonin goes up sooner in women than men.”

Duke University published a study that discovered women have a higher risk of psychological and physical issues due to a lack of sleep than men do.

“We found that for women, poor sleep is strongly associated with high levels of psychological distress, and greater feelings of hostility, depression and anger. In contrast, these feelings were not associated with the same degree of sleep disruption in men,” lead author of the study, Edward Suarez, said.

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Insights to note: The Sleep Doctor reported that melatonin levels typically rise in women “around 9 p.m., and peak during the overnight hours before falling to very low levels shortly before dawn.”

“The interaction between circadian phase and time asleep was significant for sleep efficiency, in that the circadian disruption of sleep became stronger as sleep progressed,” according to a study in PNAS Plus.

While a person sleeps, their hormone levels are being replenished, and when a woman is deprived of sleep it can mess with cycles that take place within the female body that don’t happen for men.

During the day, the adrenal glands produce the cortisol hormone that helps people have energy throughout the day, according to HealthDirect.

“The adrenals only make about 3% of a man’s testosterone while 95% come from his testicles. The adrenals make 30% of a woman’s cyclic hormones,” Flynn wrote. “What do you think it does when lack of sleep causes the body to make more cortisol? It can disrupt the production of other hormones for women and increases stress on her body.”

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The big picture: Women have been underrepresented in both circadian sleep studies and researchers are finding that women need more rest than men do.

“Women need more sleep. Unfortunately, women are taking on so much they don’t always get the sleep they need which is detrimental to their health,” Flynn wrote.