Hormones are chemical messengers that are secreted in the blood. These are then carried to the different organs and tissues, where they exert their functions.

Our hormones are responsible for many changes inside our bodies, including our sleep hormones. They regulate body temperature, growth, reproduction, sex drive, metabolism, thirst, and sexual development.

When we think about the motives for a good night’s sleep, we usually don’t ponder about our hormones playing a part in it. But several different sleep hormones that are released during sleep can affect your sleep patterns.

Sleep hormones are a group of hormones that control the quality and quantity of sleep.

Whether you are traveling overseas, had a stressful meeting, got into a fight with your partner, or snagged a promotion, our activities during the day affect the production of sleep hormones.

Understanding the connections between sleep hormones and a restful slumber may help improve the amount of good sleep you get each night.

This article here will take a look at the different sleep hormones and the role of sleep in their production. We will also talk about the changes that happen in our bodies when we go to bed.

Let’s get right to it!

What is the role of sleep in hormone production?

While we get our much-deserved sleep each night, the body works hard to recover from the day and prepare for the next. One such process is the regulation of hormones.

The amount and quality of sleep we get each night affects the production of sleep hormones. It also influences how these sleep hormones interact with each other.

During our time in bed, many sleep hormones are released into the bloodstream. These sleep hormones affect the quality of snooze we get each night.

Sleep helps us balance our appetite by maintaining optimal leptin and ghrelin levels. When we get less sleep than average, there is an urge to eat more. Sleep also controls the levels of prolactin, and its disruption can weaken the immune system, cause difficulty in concentrating, and carbohydrate cravings.

The ideal amount of sleep required for most adults is around 7 to 9 hours. You cannot catch up on sleep during the weekends if you are sleep-deprived throughout the week.

It is important to have a sufficient amount each day for optimal sleep for optimal sleep hormone regulation, including sleeping long and deep enough. Sleep that is frequently disrupted or light sleep will not help. Additionally, sleeping too much doesn’t necessarily mean better. It is important to have a sufficient amount each day for optimal sleep hormone regulation, including sleeping long and deep enough. 

What happens when you get too little sleep?

Poor sleep can wreak havoc on the internal biochemistry of the body.

Not getting enough sleep can cause reduced immunity leading to more frequent infections and other illnesses. It can also cause spikes in appetite resulting in higher calorie consumption and weight gain.

Chronic sleep deprivation can also affect your appearance. Lack of sleep increases stress hormones, breaking down the collagen protein that makes the skin smooth. Over time it can lead to dark circles under the eye and premature wrinkles.

Some more serious chronic sleep deprivation problems are diabetes, high blood pressure, heart attack, stroke, bipolar disorder, and depression.

The increased risk of these diseases can be reversed with a healthy sleeping habit.

What happens when you get too much downtime?

Sleeping too much, much like restricted sleep, can negatively influence your health. Too much sleep can lead to reduced metabolism, daytime fatigue, grogginess, disrupted sleep cycles, and impaired focus. 

Oversleeping increases the risk of heart disease, stroke, diabetes, obesity, back pain, headaches, depression, and even death.

What are the sleep hormones that regulate your slumber?

1.Estrogen and Progesterone

Estrogen and progesterone are two main female hormones that control the menstrual cycle. They are produced by the woman’s egg, fatty tissues, and adrenal glands. Lower levels of these are also present in men. They are considered to be crucial sleep hormones.

The menstrual cycle causes estrogen and progesterone to spike or drop in women. These hormones plummet as menopause approaches.

There are three types of Estrogen:

• Estradiol in childbearing women
• Estriol which is produced during pregnancy and,
• Estrone produced after menopause

Estrogen plays a role in the metabolism of neurotransmitters and feel-good hormones like serotonin, affecting our sleep-wake cycle. The female hormone has antidepressant-like effects and also helps keep the body temperature low at night. Estrogen also affects how the body utilizes magnesium, a pivotal mineral for sleep.

A decline in estrogen results in poorer mood, and lower quality of sleep. Menopausal women are at increased risk for developing insomnia due to changes in the sleep-wake cycle brought on by declining hormones.

Progesterone, another sleep hormone, helps maintain pregnancy. It is produced by the female eggs, adrenal gland, and placenta (during pregnancy). The levels reach a peak during pregnancy and after ovulation, following which they eventually decline.

Also known as a “relaxing sleep hormone,” progesterone has a mildly sedative, calming, and soothing effect. Progesterone helps make allopregnanolone, a metabolite that can produce a calming effect. It is also essential for healthy brain function and has a natural anti-anxiety effect.

It is believed that progesterone helps to fall asleep faster and sleep with fewer disruptions. Even in men, progesterone can help stimulate the respiratory system and is associated with a decrease in the frequency of sleep apnea.

2. Testosterone

Testosterone is another essential sleep hormone. It is produced in both men and women, but the levels are higher, and the effects are more pronounced in males.

Most testosterone produced in the body is released during sleep, specifically during the REM phase, which helps replenish the body and mind. Your testosterone levels increase as you sleep and decrease the longer you are awake.

Low levels of testosterone are associated with fewer deep sleep cycles and low-quality sleep. Researchers have also observed that as testosterone goes down, the levels of cortisol rise (more on that below). 

It doesn’t take long for poor sleep to derail the sleep hormone levels. According to a 2014 study, there was a 10-15% decrease in testosterone production for eight days after sleeping for less than 5.5 hours. The dip in testosterone levels was because they could not stay in a deep sleep long enough to receive the natural benefits that come with it.

Reduced levels of this male sleep hormone are also linked to snoring, leading to an endless cycle of poor sleep and low testosterone.

3.Cortisol and melatonin

The adrenal glands, located just above the kidneys, produce stress-related hormones such as cortisol. But why is it that when you are stressed out, you will find yourself having difficulty falling asleep and sleeping through the night?

Cortisol is a key sleep hormone. The right amount of this sleep hormone at the right time is essential to balance sleep hormones. But if sleep loss and cortisol are not managed, it leads to a vicious cycle.

The levels of cortisol ebb and flow over 24 hours to dictate our sleep-wake cycle. This rise and fall of cortisol are important to help us fall asleep by our bedtime, sleep throughout the night and wake up in the morning.

The production of cortisol temporarily spikes in the morning, which helps you feel awake and refreshed. As you approach your bedtime, the level reduces.

A higher cortisol level around nighttime contributes to wakefulness, resulting in shallower and shorter sleep.

Along with cortisol, melatonin is another sleep hormone. These hormones work together and play a key role in regulating sleep patterns.

Melatonin is made by the pineal gland, a pea-sized gland in our brain. When the nerves in our eyes detect natural light diminishing, it will send the message to the part of the brain that releases melatonin. As you prepare for sleep, melatonin helps you relax and makes you drowsy.

As the production of melatonin ramps up as you approach bedtime, cortisol production declines. In the morning, when you wake up, the reverse happens.

It is extremely easy to disrupt the normal balance of cortisol and melatonin. Stress can act as a catalyst for your fight or flight response, triggering the release of cortisol and decreasing melatonin. Sugary snacks before bedtime can also stimulate cortisol production.

Interestingly, computers, smartphones, and tablets emit blue light that tricks your brain into believing it is still daylight. Scrolling through social media or watching a movie right before bed hampers the production of melatonin, keeping you wide awake at night!

4. Insulin

While most of us are familiar with the role of insulin in regulating our blood sugar levels, many are unaware that it acts as a sleep hormone too! Insulin is produced by the pancreas and helps the body utilize sugars.

Blood sugar levels surge during sleep. In a healthy person, insulin handles this sugar spike by letting the muscles, liver, and fat cells absorb glucose from the blood.

Sleep deprivation increases blood sugar by decreasing the sensitivity of cells to insulin. Studies have even suggested that those who sleep less than 6 hours per night have irregular sleeping habits. They snack more, eat unhealthily, and raise the risk of diabetes.

Similar to cortisol and testosterone, sleep and insulin can exist in a vicious cycle. Sleep deprivation encourages unhealthy eating, which spikes blood sugar. This triggers insulin release, which will cause further sleep problems as your blood sugar fluctuates throughout the night, causing more disturbances to your sleep hormones!

5. Thyroid hormones

The thyroid is a small butterfly-shaped gland in the front part of your neck. It releases hormones, collectively known as the thyroid hormone, influencing metabolism and brain development. But did you know they are also regarded as one of the sleep hormones?

When your thyroid gland is too active (also known as hyperthyroidism), or not producing enough hormones (also known as hypothyroidism), it can cause many different symptoms. Both these conditions are even linked with poor sleep.

Let’s start with hypothyroidism. When the thyroid is not active enough, your metabolism is sluggish. It is often associated with fatigue and lethargy, which may sound like you will get a good night’s sleep, but unfortunately, that is not the case.

Hypothyroidism can affect your sleep by making you feel too cold. This may lead to muscle and joint pain, and you may have difficulty falling asleep or not sleeping adequately to feel rested.

On the other hand, hyperthyroidism causes you to display symptoms of irritability or nervousness. You tend to sweat a lot and can feel your heart pounding inside your chest. This can act as a stimulant for the nervous system making it difficult to fall asleep or get adequate sleep, further disturbing your sleep hormones.

What happens to your body when you sleep?

When you sleep, hormones flood your body. Hormones like melatonin and growth hormones are released, helping you sleep, grow and repair yourself. Other hormones like cortisol decrease during the first few hours of sleep before peaking soon after you wake up.

During sleep, antidiuretic hormone (ADH) is released from the brain, which switches off the need to run to the loo to pee. Your sympathetic nervous system (the one that controls your fight or flight response) relaxes. Your brain processes and sorts the day’s information, helping you create long-term memories. This process can signify that the body is a state of balance, therefore, balancing your sleep hormones.

The takeaway

A night of good sleep is vital for physical and mental health, and your body does many important things while you are asleep. Many hormones in the body play a key role in regulating sleep.

Estrogen, progesterone, testosterone, cortisol, melatonin, insulin, and thyroid hormone levels influence sleep quality and pattern. In turn, too little time or too much time under the cover can influence these sleep hormones. Like a vicious cycle: sleep impacts hormones, and hormones affect our sleep.

If you have trouble falling asleep, staying asleep, or do not feel well-rested when you get up in the morning, talk to your doctor. The chances are that there is an underlying issue with the sleep hormones creating potential health problems.

References

1. Kitamura S, et al. (2016). Estimating individual optimal sleep duration and potential sleep debt. DOI:10.1038/srep35812
2. Andersen, M L et al. “Effects of progesterone on sleep: a possible pharmacological treatment for sleep-breathing disorders?.” Current medicinal chemistry vol. 13,29 (2006): 3575-82. doi:10.2174/092986706779026200
3. Leproult, Rachel, and Eve Van Cauter. “Effect of 1 week of sleep restriction on testosterone levels in young healthy men.” JAMA vol. 305,21 (2011): 2173-4. doi:10.1001/jama.2011.710
4. Wittert, Gary. “The relationship between sleep disorders and testosterone in men.” Asian journal of andrology vol. 16,2 (2014): 262-5. doi:10.4103/1008-682X.122586