Rest & Relaxation

Here’s How Our Hormones Help Get Us To Sleep

Lesson 6 Chapter 2


Hormones Are Really Important

When it comes to motives for getting a good night’s sleep, you don’t usually think about your body’s hormones. But sleep allows many of your hormones to replenish so you have the optimal energy, immunity, appetite and coping ability to face the day’s highs and lows. The activities we do during the day - from having a fight with a partner, using our Smart Phones at night, running in a race, to travelling overseas - also affect our hormone levels and, in turn, our quality of sleep.

Main Hormones Involved In Sleep Quality


Adrenocorticotropic Hormone (ACTH)









Chemical Messages

Your body’s hormones are like chemical messages in the bloodstream which cause a change in a particular cell or organ and surrounding tissues. The hormone adrenaline, for example, is produced by the adrenal glands (on top of the kidneys) and helps prepare the body’s 'fight or flight' response during times of stress.


Adrenaline And Cortisol

Some hormones, such as adrenaline, make you feel more alert and prepared for action. This then makes it hard for you to go to sleep. To prevent this effect it’s best to do relaxing activities before bedtime, rather than stressful work tasks or intense exercise. When stress is long lasting, adrenocorticotrophic hormone within the pituitary gland (attached to the base of the brain) triggers the release of cortisone and cortisol from the adrenal glands.

Levels of adrenocorticotrophic hormone tend be higher in people with insomnia than in good sleepers. This suggests that excessive arousal and ongoing stressors contribute to the insomnia. Top level athletes can have difficulty getting to sleep because they tend to have high levels of cortisol throughout the day, including in the evening.


Hormones Released During Sleep Boost Your Immune System And Prevent Hunger

Sleep is a time when several of the body’s hormones are released into the bloodstream. These include growth hormone, which is essential for growth and tissue repair, including in adults. 

Sleep helps to balance your appetite by maintaining optimal levels of the hormones ghrelin and leptin. So, when we get less sleep than normal we may feel an urge to eat more.

Sleep also controls levels of the hormones insulin and cortisol so that you wake up hungry, prompting you to eat breakfast, and preparing you for facing daytime stress. If you get less sleep than normal your levels of prolactin may get out of balance and you can end up with a weakened immune system, difficulty concentrating and carbohydrate cravings during the day.


Hormones Make You Feel Sleepy At Night

Hormone levels also influence the timing of when we feel sleepy and awake - our body clock or sleep-wake cycle. The hormone melatonin is released with darkness and tells our body it’s time to sleep. This is why being around too much bright light before bed can affect our sleep as it can stop the release of melatonin. It’s also why it can be hard for night-time shift workers to sleep during the day.


For Women, Changes In Sex Hormones Affect Sleep

The relationship between hormones and the sleep-wake cycle in women is further influenced by the menstrual cycle. Just before a woman’s period, hormonal changes, including the sudden drop in levels of progesterone, affect the body’s temperature control, which in turn can reduce the amount of 'REM' sleep. This is the stage of sleep when most of our dreams occur.

For women with severe premenstrual symptoms reduced levels of melatonin before bedtime just before their menstrual period can cause poor sleep, including night-time awakenings or daytime sleepiness.


For Men, Testosterone Levels Affect Sleep

For men, levels of testosterone are highest during sleep and require at least three hours sleep to reach this peak. Low levels of testosterone in men, which can occur with sleep deprivation, ageing, and physical problems, have been associated with a reduction in sleep efficiency and changes to the stages of sleep men experience. Testosterone can be taken as a supplement but abuse of it can lead to other sleep and health problems.

By doing things to promote good sleep, such as reducing stress, engaging in relaxing evening routines before bed, going to bed and getting up at regular times, you can facilitate the replenishing activities of your hormones that help you make the most of your day and optimise your well-being.