You lie down, ready to put your mind to rest and end another chaotic day.
You close your eyes, think good things, and drift off—but while your mind rests, your body gets to work.
There’s always a lot going on at any given moment in your body, but the timeline of hormone production at night is a fascinating look into everything your body does to get you the best sleep possible. Hormones, your body’s chemical messengers, are constantly at work to regulate your sleep-wake cycle, and they all run based on your own circadian rhythm.
Poor quality sleep can be one of the symptoms of hormone imbalance, so if you feel like your systems aren't quite firing on all cylinders, contact your doctor.
Why do we wake up in the morning? There are two hormones that generally oppose each other and stay in a constant balance to regulate when you go to bed and when you wake up. The level of melatonin, the sleep hormone, in your system steadily rises as you lose sunlight exposure in the evening. Cortisol, the stress hormone, lowers as it gets dark. When melatonin is high and cortisol is low, you’re able to drift off to sleep. This is a huge part of why we struggle to get to sleep when we’re feeling stressed—high levels of cortisol can actively fight against melatonin.
Once you do fall asleep, your melatonin levels gradually start to fade, helping your sleep pattern regulate until you’re body has rested enough. As the melatonin falls off overnight, your body produces more cortisol. Your cortisol levels peak in the early morning, right before you wake up. This peak acts as the wake-up signal for your brain and body to hop to it and get moving.
Some people take melatonin supplements to help sleep better as there isn’t a known side effect of melatonin.
While these are the two main players to get you to sleep and wake you up, there are plenty of other hormones that start working while you sleep to regulate other bodily functions.
What other hormones are we producing while we sleep? Your body is not only resting and restoring energy while you sleep—it’s preparing you for the next day.
Two hormones that regulate your hunger and weight can be found working away overnight. Leptin is a hormone that helps tell your brain when you’re full, when to burn calories, and when to create energy. Ghrelin balances out leptin, telling your brain when you’re hungry, when to stop burning calories, and when to conserve energy.
During sleep, your leptin levels increase and communicate to your brain that your body has plenty of energy and prevent you from feeling hungry. Sleeping lowers ghrelin, so that you aren’t constantly hungry and feeling like you need to eat more.
Sleep deprivation disrupts the balance between these hormones, causing you to feel hungry when you’re not and leading to all sorts of other issues. Eating when you’ve already consumed enough energy causes weight gain—obesity has been linked to sleep disorders in recent studies for this very reason.
If you’re wondering how to reduce ghrelin—and you may be, it’s logical that suppressing hunger can help with weight management—avoiding sugar and focusing on protein can help reduce your ghrelin production.
Insulin is another hormone controlled by sleep. Good, restorative sleep creates an insulin response that makes you hungry first thing in the morning, perfect for breakfast. Insulin also controls your glucose levels, maintaining how your body uses carbs and fats.
Hormone changes overnight impact men and women differently Sex hormones have important roles to play while you sleep, as well. Women often have a harder time getting good sleep because of the constant fluctuation of hormones. Progesterone falls before a menstrual cycle, which can destabilize your internal temperature control, making it harder to get comfortable at night.
High levels of progesterone and estrogen during pregnancy can cause you to feel more tired during the day, and even lead to snoring at night.
In men, testosterone levels increase while sleeping and peak around a third of the way through your typical sleep cycle. Men who struggle to get enough sleep may find that they have lower testosterone.
Adrenal fatigue can keep you up at night Your adrenal glands secrete cortisol—the hormone that we already know relates to stress and being awake. Adrenal fatigue can lower the amount of hormone produced, impacting your sleep-wake cycle and creating quite the problem. Low cortisol levels can be just as disruptive as high levels.
Symptoms of adrenal fatigue include:
- Unexplained weight loss
- Body aches and pains
- Body hair loss
- Low blood pressure
- Skin discoloration
Chronic stress can cause similar symptoms, so if you have any suspicion that your inability to sleep may be caused by onset stress or adrenal fatigue, contact your doctor.