Nearly a third of the UK population suffers from insomnia. Find out whether hormones are contributing to your sleep loss.
The Cortisol–Melatonin Rhythm
In a perfect world, the master stress hormone cortisol should be in sync with the master sleep hormone melatonin. Each hormone counter-balances the other in a precise rhythm — when cortisol is high, melatonin should be low, and when melatonin is high, cortisol should be low.
For many, this rhythm is out of balance. With an estimated 60 million Americans suffering from some degree of sleep loss and nearly a third of the UK population suffering from insomnia affecting their health, it is surprising that so many are still unaware of the connection between hormones and sleep.
The Consequences of Chronic Sleep Loss
According to the Department of Health & Human Services, over a third of US adults report daytime sleepiness so severe it interferes with work, decision making and social functioning. Depression, obesity and diabetes are just three of the long-term consequences of sleep deprivation — defined as six or fewer hours per night.
Hormone-Related Causes of Sleep Disturbances
High Cortisol
Elevated cortisol — particularly at night — is one of the most common hormonal drivers of insomnia. High cortisol results in insomnia, anxiety, sugar cravings, feeling tired but wired, and increased belly fat. Cortisol should naturally decline through the evening to allow melatonin to rise. When chronic stress keeps cortisol elevated, this transition is disrupted and sleep quality suffers.
Our Adrenal Stress Profile (Saliva) measures cortisol at four time points across the day — including the critical evening reading — alongside DHEA-S, giving you and your practitioner a clear picture of whether adrenal dysrhythmia is driving your sleep problems.
Low Melatonin
Melatonin is produced by the pineal gland in response to darkness and signals the body that it is time to sleep. Low melatonin results in excessive fatigue, depression, anxiety and insomnia. Factors that suppress melatonin production include blue light exposure, elevated cortisol, low vitamin D and nutritional deficiencies in the serotonin pathway.
Our Sleep Balance Profile Test measures melatonin (as its urinary metabolite MT6s) alongside cortisol and other key hormones involved in the sleep-wake cycle — providing a comprehensive hormonal picture of what may be driving your insomnia.
Neurotransmitter Imbalance
Changes in sex steroid hormone levels during perimenopause and menopause can significantly impact neurotransmitter levels, leading to recurring sleep issues. Declining estradiol reduces serotonin availability — the precursor to melatonin — while low progesterone removes its natural sedative effect via the neuroactive steroid allopregnanolone. Low GABA, elevated glutamate and disrupted dopamine rhythms can all contribute to difficulty falling or staying asleep.
If you are experiencing sleep disturbances alongside other menopausal symptoms, our Menopause hormone testing page explains which tests are most relevant to your stage of life and how to interpret your results in context.
Taking Action
Hormonal sleep disturbances are not something you simply have to accept. With the right testing, the root cause of your insomnia can be identified — whether it is high night-time cortisol, low melatonin, neurotransmitter imbalance or declining sex hormones. From there, targeted interventions — whether lifestyle changes, nutritional support or hormone therapy — can help restore the rhythm your body needs for restorative sleep.
Originally ZRT Laboratory. Reproduced with permission. Last reviewed: May 2026.