Melatonin Sleep Hormone – what it does and what cancels it.


March 21, 2023

Melatonin Sleep Hormone

What is Melatonin Sleep Hormone?

Melatonin is a naturally occurring hormone our brains produce to prepare us for sleep.

When melatonin hits the bloodstream (typically a few hours before bedtime), it reduces alertness and “facilitates our ability to fall asleep,” explains David Neubauer, M.D., associate professor of psychiatry and behavioral sciences at Johns Hopkins Medicine. It also helps cool off the brain and the body, “which helps you sleep better,” says James K. Wyatt, director of the Section of Sleep Disorders and Sleep-Wake Research at Rush University in Chicago.

What cancels naturally occurring melatonin sleep hormone?

Because melatonin is triggered by darkness, being exposed to light at night can block melatonin production, especially the blue light from digital devices such as cell phones. 

Conditions such as Alzheimer’s disease and diabetes and medications such as nonsteroidal anti-inflammatory drugs and beta-blockers stop the body from producing melatonin during the night. This can make falling and staying asleep difficult.

Do Melatonin Supplements work? 

Melatonin dietary supplements can be made from animals or microorganisms, but most often they’re made synthetically. Melatonin supplements may help with certain conditions, such as jet lag, delayed sleep-wake phase disorder, some sleep disorders in children, and anxiety before and after surgery. However, this popular supplement comes with side effects and questions about it’s effectiveness.

According to practice guidelines from the American Academy of Sleep Medicine (2017) and the American College of Physicians (2016), there’s not enough evidence on the effectiveness or safety of melatonin supplementation for chronic insomnia to recommend its use. Instead, The American College of Physicians’ guidelines strongly recommend the use of cognitive behavioral therapy for insomnia (CBT-I) as an initial treatment for insomnia.

Is it safe to take melatonin supplements?

“We know that melatonin is often used as a sleep aid, but it’s actually misused as a sleep aid because it’s not a sleep aid,” says Naima Covassin, a coauthor of the study and a sleep disorder expert at Mayo Clinic.

Popping a melatonin pill or gummy before bedtime may help you fall asleep a few minutes faster, Covassin says, but it won’t make much of a difference in the number of times you’re waking up at night or how many total hours you’re getting. There’s actually very little improvement in all of these parameters, she adds.

For melatonin supplements, particularly at doses higher than what the body normally produces, there’s not enough information yet about possible side effects to have a clear picture of overall safety. Short-term use of melatonin supplements appears to be safe for most people, but information on the long-term safety of supplementing with melatonin is lacking.

Also keep in mind:

  • Interactions with medicines
    As with all dietary supplements, people who are taking medicine should consult their health care providers before using melatonin. In particular, people with epilepsy and those taking blood thinner medications need to be under medical supervision when taking melatonin supplements.
  • Possible allergic reaction risk
    There may be a risk of allergic reactions to melatonin supplements.
  • Safety concerns for pregnant and breastfeeding women
    There’s been a lack of research on the safety of melatonin use in pregnant or breastfeeding women.
  • Safety concerns for older people
    The 2015 guidelines by the American Academy of Sleep Medicine recommend against melatonin use by people with dementia.
    Melatonin may stay active in older people longer than in younger people and cause daytime drowsiness.
  • Melatonin is regulated as a dietary supplement
    In the United States, melatonin is considered a dietary supplement. This means that it’s regulated less strictly by the Food and Drug Administration (FDA) than a prescription or over-the-counter drug would be. In several other countries, melatonin is available only with a prescription and is considered a drug.
  • Products may not contain what’s listed on the label
    Some melatonin supplements may not contain what’s listed on the product label. A 2017 study tested 31 different melatonin supplements bought from grocery stores and pharmacies. For most of the supplements, the amount of melatonin in the product didn’t match what was listed on the product label. Also, 26 percent of the supplements contained serotonin, a hormone that can have harmful effects even at relatively low levels.

How can I reduce the negative effects of blue light?

As mentioned earlier, exposure to blue light before bedtime also can disrupt sleep patterns as it affects when our bodies create melatonin. Interruption of the circadian system plays a role in the development of type 2 diabetes, cardiovascular disease, cancer, sleep disorders, and cognitive dysfunctions.

  • Get blue-light filters for your smartphone, tablet, and computer screen. The filters prevent much of blue light from reaching your eyes without affecting the visibility of the display.
  • Follow the 20-20-20 rule to reduce digital eye strain. Take a 20-second break to view something 20 feet away every 20 minutes.
  • Control lighting and glare on your device screen. Set up a good working distance and posture for screen viewing. Confirm that even minor vision problems are properly corrected.
  • Talk with your eye doctor about blue light protection and digital device use at your next eye examination.


We hope this information is helpful to you in the important work you do as a family caregiver.
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