Melatonin: How It Helps With Sleep And Insomnia

Introduction: Why is sleep important?

The amount of sleep we get is crucial in maintaining a healthy lifestyle. Having a good night’s sleep enables one to feel refreshed and allows the body to recover. Although sleep needs may differ for every individual, in general, a healthy adult requires around 7 hours of uninterrupted rest [1]. However, sleep disorders such as insomnia is especially prevalent in the modern-day society. The United States (U.S.) Centers for Disease Control and Prevention’s (CDC) estimated that about one-third of the adult population has insomnia [2], while an analysis conducted in the Netherlands reported that about a quarter of the adult population (in the Netherlands, US, and the United Kingdom) slept less than the age-specific recommended sleep duration [3]. This number is likely to be even higher in elderly, with reports of up to 48% suffering from insomnia [4].

Diagnoses of insomnia usually fall within the few types as below [5]:

• Sleep-onset insomnia – this occurs when one has trouble falling asleep
• Sleep-maintenance insomnia – this refers to one having difficult staying asleep through the night
• Mixed-type insomnia – a hybrid condition of the above-mentioned types of insomnia

Some may also classify insomnia based on the duration of the symptoms and divide it into either acute insomnia or chronic insomnia.

Having insufficient sleep can be detrimental to your health. You may be able to connect the dots between the lack of sleep and the subsequent risks of getting into road traffic accidents more easily due to the lack of focus [6]. Other than your daily functioning, there are many more long-term health complications of having insufficient sleep. There are many studies linking a lack of sleep with many diseases, such as obesity, diabetes, cardiovascular conditions (such as heart attacks and strokes), anxiety, and many more [7].

What is Melatonin?

One common health supplement to help manage insomnia is melatonin. Melatonin is a hormone that is produced and regulated by the pineal gland, a small pea-sized gland located in our brain [8]. This hormone is produced in response to darkness (i.e., more melatonin is produced with less light). When you are exposed to light at around your bedtime, the production of melatonin can be blocked which may make it harder for you to fall asleep [9].

Functions of Melatonin

The best-known function of melatonin is to maintain sleep rhythms and cycles (called circadian rhythms) [9]. It has been demonstrated to have clock-phase resetting and sleep-promoting functions, which serves as a ‘time-cue’ for the body to go into sleep mode [10]. Melatonin production is also lowered in elderly with insomnia [11].

Experts have suggested the use of melatonin as a first-line management for sleep-onset insomnia in certain groups of people, such as the elderly or those with cognitive dysfunction [12]. Other possible use of melatonin includes in people with jet lag [13], and a condition known as Delayed Sleep-Wake Phase Disorder (DSWPD) [14].

Is Melatonin safe? How much is enough?

Melatonin, being a naturally occurring hormone that is produced in your body, is generally regarded as safe [9]. Studies and analyses have concluded that the most frequently reported adverse effects include daytime sleepiness, headache, and dizziness [15].

Dosing of melatonin typically range from 1mg to 5mg, but products in the market can go as low as 0.2mg and as high as 20mg [12].

Conclusion

Insomnia is a very common problem faced by 1 in 3 adults, which can have severe and long-term complications if one is chronically lacking sleep. Melatonin is a hormone produced by the pineal gland in the brain that is available as a dietary supplement, which can regulate the body’s circadian rhythm. This can potentially help the body initiate sleep faster. Generally regarded as safe, it is available in the market in various doses and dosage forms.

References

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2. United States (U.S.) Centers for Disease Control and Prevention’s (CDC) Morbidity and Mortality Weekly Report. 1 in 3 adults don’t get enough sleep. 2016 February. Available on: https://www.cdc.gov/media/releases/2016/p0215-enough-sleep.html
3. Kocevska, D., Lysen, T.S., Dotinga, A et al. Sleep characteristics across the lifespan in 1.1 million people from the Netherlands, United Kingdom and United States: a systematic review and meta-analysis. Nature Human Behaviour. 2021;5(1):113-122.
4. Patel D, Steinberg J, Patel P. Insomnia in the Elderly: A Review. J Clin Sleep Med. 2018 Jun 15;14(6):1017-1024.
5. Sleep Foundation. Insomnia: What it is, how it affects you, and how to help you get back your restful nights. 2022 January. Available on: https://www.sleepfoundation.org/insomnia
6. de Mello MT, Narciso FV, Tufik S, et al. Sleep disorders as a cause of motor vehicle collisions. Int J Prev Med. 2013;4(3):246-257.
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8. 5 Functions of the Pineal Gland. 2017 April. Available on: https://www.healthline.com/health/pineal-gland-function
9. National Center for Complementary and Integrative Health (NCCIH). Melatonin: What You Need To Know. 2021 January. Available on: https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know
10. Zisapel N. Sleep and sleep disturbances: biological basis and clinical implications. Cell Mol Life Sci. 2007 May;64(10):1174-86.
11. Leger D, Laudon M, Zisapel N. Nocturnal 6-sulfatoxymelatonin excretion in insomnia and its relation to the response to melatonin replacement therapy. Am J Med. 2004 Jan 15;116(2):91-5.
12. Neubauer DN et al. UpToDate: Pharmacotherapy for insomnia in adults. 2022 March.
13. Herxheimer A. Jet lag. BMJ Clin Evid. 2014 Apr 29;2014:2303.
14. Auger RR, Burgess HJ, Emens JS, et al. Clinical Practice Guideline for the Treatment of Intrinsic Circadian Rhythm Sleep-Wake Disorders: Advanced Sleep-Wake Phase Disorder (ASWPD), Delayed Sleep-Wake Phase Disorder (DSWPD), Non-24-Hour Sleep-Wake Rhythm Disorder (N24SWD), and Irregular Sleep-Wake Rhythm Disorder (ISWRD). An Update for 2015: An American Academy of Sleep Medicine Clinical Practice Guideline. J Clin Sleep Med. 2015 Oct 15;11(10):1199-236
15. Besag FMC, Vasey MJ, Lao KSJ, Wong ICK. Adverse Events Associated with Melatonin for the Treatment of Primary or Secondary Sleep Disorders: A Systematic Review. CNS Drugs. 2019 Dec;33(12):1167-1186