Melatonin: The Sleep/Wake Cycle Hormone

May 04, 2022

Melatonin: The Sleep/Wake Cycle Hormone

Why is Sleep Important and How Much Do We Really Need?

Getting a good night’s sleep is a goal of many Americans, however recent reports from the CDC shows that one out of three American adults (aged 18-60 years old) do not achieve the recommended 7-9 hours of sleep per night that is needed for optimal health and wellbeing. Up to 62% of Americans feel sleepy on an average of three times per week leaving them feeling irritable, tired, and with headaches.1 Adults who sleep less than 7 hours per night have an increased risk of developing a variety of chronic conditions such as diabetes, high blood pressure, obesity, and frequent mental distress.2

Sleep Lifestyle Habits and Rituals to Support Rest

Healthcare practitioners should advise patients with disrupted sleep patterns or those who cannot seem to get the recommended 7-9 hours of sleep per night to eat healthy meals at the same time each day. It is also important to maintain a regular sleep schedule, relax before bedtime, avoid blue light from devices, or screens in general before bed that can hinder the body’s natural production of melatonin and avoid stimulants such as caffeine and nicotine.3 A good sleep environment that is free of distractions will help to establish better sleep each night. When sleep habits do not allow you to achieve the optimal sleep desired, melatonin as a supplement can be considered to help with a variety of sleep needs including falling asleep faster, improving sleep quality, and supporting restful sleep. A meta-analysis of 19 studies concluded that melatonin reduces the amount of time it takes to fall sleep (sleep latency), increases total sleep time, and improves overall sleep quality.4

Healthy Sleep Tips

What is Melatonin?

Melatonin is a hormone naturally produced by the pineal gland in the brain, in response to darkness. It plays a key role in regulating the body’s circadian rhythm, your internal clock that regulates your daily sleep/wake cycle.5 The body has daily rhythms, including sleep, which are regulated by the internal clock located in the suprachiasmatic nucleus (SCN) within the brain. The SCN sends signals to the pineal gland to increase nocturnal production of melatonin in response to light queues. When the sun sets each day and darkness sets in, signals through the optic nerve tell the brain to start producing melatonin, which promotes healthy sleep. The pineal gland continues to produce melatonin throughout the night until the sun comes up. As daylight sets in, the pineal gland instructs the brain to decrease melatonin production while simultaneously increasing the hormone cortisol signaling our body that it’s time to wake up.

Natural Melatonin Cycle

A good night’s sleep is needed to support a healthy immune system by allowing the body to absorb and utilize immune supporting nutrients throughout the night. Melatonin receptors are found throughout the body to help synchronize the body’s circadian rhythm and other physiological functions including calibration of the immune system, while the body is resting. According to a recent study, those who sleep less than six hours a night are 4.2 times more likely to catch the common cold compared to those who sleep more than seven hours per night. Further those who sleep less than five hours were 4.5 times more likely to catch the common cold compared to those who sleep more than seven hours per night.6

Although the body naturally makes this important hormone, researchers and the public have become increasingly interested in taking external sources of melatonin to help with sleep issues. A meta-analysis of 19 studies concluded that melatonin reduces the amount of time it takes to fall sleep (sleep latency), increases total sleep time and improves overall sleep quality.4

Melatonin is widely available in a variety of forms including tablets, capsules, gummies and powders. Melatonin dietary supplements are an alternative to OTC and Rx sleep medications that can have potentially serious side effects and possibly be habit forming.

Who Might Benefit from Taking Melatonin?

Jetlag7: Research suggests that melatonin supplements may help with jet lag which affects those who travel across multiple time zones. Those who do such travel may experience disturbed sleep, daytime sleepiness and subsequent impaired functioning. Taking melatonin before sleep may help your body adjust to the time change.7

Shift workers7: Those who work the night shift may find benefit in taking melatonin to help rebalance the sleep/wake cycle. Shift work involves working the night shift which may cause people to feel sleepy at work and also make it difficult to sleep during the daytime after the shift ends.

Delayed sleep-wake phase disorder (DSWPD)7: People with DSWPD have trouble falling asleep at the usual times and waking up in the morning. They typically have difficulty getting to sleep before 2 a.m. to 6 a.m. and would prefer to wake up between 10 a.m. and 1 p.m. Melatonin supplements may help with sleep in people with DSWPD based on the following research:

  • A 2016 review that looked at a small number of people (52) from two studies showed that melatonin supplements reduced the time it took for those with DSWPD to fall asleep when compared to on average, it took about 22 minutes less for them to fall asleep.
  • A 2018 randomized controlled trial that lasted 4 weeks included 307 people with DSWPD and found that taking melatonin 1 hour before the desired bedtime combined with going to bed at a set time led to improvements included falling asleep an average of 34 minutes earlier, better sleep during the first third of the night, and better daytime functioning.

Melatonin and Children

Sleep disorders experienced by children and adolescents may lead to undesirable effects in behavior, and their ability to function during the day, including difficulty concentrating. Disrupted sleep or sleep related issues can impact overall health and wellbeing. Often, good bedtime habits and parent education, including setting a healthy bedtime routine, can help. However, when these efforts do not resolve the sleep issue, melatonin can be considered to add to the bedtime regimen with ongoing supervision with a health care practitioner.

There has been some promising research showing that short-term use of melatonin is effective and well-tolerated for treatment for children and adolescents with difficulty falling asleep.8 Other research has shown that melatonin may be especially helpful for children with conditions that can impact their ability to fall asleep.8,9 Melatonin’s use in these circumstances should be discussed and carefully monitored by the child’s healthcare practitioner.

Melatonin Dosage

Adults: The safe amount of melatonin ranges in doses of 0.2–10 mg per day.10,11 It is best to start with a small dose (0.2-5mg) and then increase if needed, to find what dose works best. It is recommended that melatonin be taken 30 minutes to 1 hour before bedtime. Melatonin in doses up to 10 mg can be safely taken for up to 2 months. If sleep issues are ongoing beyond 2 months, there may be other health issues going on that should be addressed with a healthcare practitioner.

Children/Adolescents: Melatonin use can be used for children and adolescents and is recommended to start at the lowest dose (.2-1.0 grams) and increase if needed under the ongoing supervision of a healthcare practitioner. Melatonin has most often been used for children in doses of up to 3 mg for up to 3 months.12 Melatonin use is highly individualized according to multiple factors such as severity and type of sleep disorder, and any associated neurological pathology. According to a 2015 study, children less than 88 pounds should take a maximum dosage of three milligrams, and children weighing more than 88 pounds should take a maximum dosage of five milligrams.13 This study concluded that melatonin reduced the amount of time it takes to fall asleep and increases total sleep time but did not reduce night awakenings.

Melatonin Safety

While melatonin is generally considered safe, there are important considerations to be aware of:

  • Women who are pregnant, attempting to become pregnant or breastfeeding should not take 14
  • Individuals should not drive a motor vehicle or operate machinery within 8 hours of taking
  • Those with chronic conditions should be under the supervision with their healthcare practitioner. consult with and be monitored by their healthcare practitioner prior to using melatonin, including hypertension, auto-immune, depressive, bleeding or seizure disorders.14
  • For people with dementia, the 2017 guidelines by the American Academy of Sleep Medicine recommend against using melatonin.15

Possible Side Effects

Research shows that the side effects of taking melatonin are mild, and may include dizziness, headache, nausea.7 Though less common, other side effects of taking melatonin might include abdominal cramps, abnormally low or elevated blood pressure, confusion/disorientation, irritability, mild anxiety, mild tremor, reduced alertness, and short-lasting feelings of depression.5 Since melatonin can cause daytime drowsiness, you shouldn’t drive or operate machinery within eight hours of taking it.

Potential Drug Interactions

Melatonin can interfere with a variety of medications and is therefore essential to consult with your health care professional if you are taking any of the following:16,17

  1. Blood pressure medication (antihypertensives): Melatonin may impair the efficacy of some calcium channel blockers. Monitor for changes in therapeutic efficacy and adjust doses as necessary and/or avoid use of melatonin with this drug class.
  2. Antidepressants: Melatonin may interact with medications that inhibit serotonin reuptake including several antidepressant medications. Endogenous melatonin levels are reduced by SSRI medications.
  3. Anticonvulsants: Taking melatonin with these medications may increase the risk of
  4. Immunosuppressants: Melatonin may interfere with immunosuppressive therapy
  5. Antidiabetic Meds: Melatonin might increase risk of hypoglycemia
  6. Warfarin: Melatonin may have antiplatelet effects and may increase risk of bleeding

Should I Add a Melatonin Dietary Supplement to My Daily Routine?

It’s important for patients to communicate with their healthcare professionals about any changes to their daily regimen including dietary supplements. Work together to understand personal nutrition needs as well as current dietary patterns to identify nutrient gaps. For those who are still unable to meet their nutrient needs from diet alone, it’s important to discuss the need to fill any potential nutrient gaps with dietary supplements, as a safe and effective way to ensure adequate intake of all essential nutrients.

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