Your Guide to Melatonin

Melatonin seems to be all the rage when it comes to insomnia and sleep problems. However, it’s good to be aware that the most popular treatments are not necessarily the most effective – they’re just the ones best marketed. With any supplement or treatment I recommend, I always want to make sure it is backed with clinical efficacy, research, and/or traditional knowledge. But before I get into that, let’s get into the basics of melatonin first.

What is melatonin?

Melatonin is a hormone primarily produced in the pineal gland in the brain, but is also found in other organs and tissues such as the retina, intestine, and salivary glands. Tryptophan is converted to serotonin, which is eventually converted to N-acetyl-5-methoxytryptamine (melatonin). It is known for its connection in our body’s circadian rhythms, as well as a important antioxidant [1]. Melatonin is termed a “chronobiotic”. This means that it helps establish sleep-wake patterns and sends our body signals about what time of day it is to optimize physiological processes. Melatonin is secreted at night during darkness, and is therefore associated with sleep, changes in body temperature, and shifts in the cortisol release pattern (which is the exact opposite of melatonin) [2]. Because it also crosses the blood-brain barrier and has a high safety profile at its highest dosage, melatonin has great potential for clinical application in neurodegenerative disorders [3-4].

Melatonin supplements

Supplements range from liquid to tablets, and usually from 1mg to 10mg in dosage strength. The optimal dosing varies greatly, and if there’s one thing I’d like you to remember, it is this: more isn’t necessarily better. Many people think that if their insomnia has been a problem for numerous years, and that they’ve tried so many treatments with no effect, they MUST need the highest possible dose to see any results with melatonin. This is a common misconception. Keep in mind that melatonin is a HORMONE, and each body is different, with a different susceptibility and sensitivity to it.

Taking a dose that’s too high (or taking melatonin in general) can leave you with some negative side effects, including intense, vivid dreams, drowsiness, a “groggy” feeling the next morning, and still feeling the need to sleep when you wake up. This is a sign that you may need to adjust the dose or alter the timing of your dosing, and it is always recommended to do this under the care of a naturopathic doctor.

What is it used for?

Melatonin is used for many things, not just sleep! For example, really high doses are used for cancer care [5]. There’s even some potential for its role in diabetes and insulin secretion [6] and GERD (“heart burn”) [7]. There are numerous studies on melatonin’s role in fertility and reproductive health, with evidence for improving fertilization and embryo quality [8] and decreasing oxidative damage to sperm DNA (improving sperm quality) [9]. As the pineal gland matures after birth, the embryo and fetus depend on maternal melatonin. Disruption in melatonin circadian rhythm (by continuous light exposure, for example) interferes with intrauterine growth and normal adrenal response to ACTH in animal studies. These changes were reversed with daily supplementation of melatonin at the subjective night time [10].

As for insomnia – your internal melatonin status will be a factor in whether supplementation will be effective or not. An example would be if you are on beta-blockers (high blood pressure medication), which suppress our body’s night time melatonin secretion. As a result, many report insomnia as a side effect. Supplementation for 3 weeks in this population was shown to increase total sleep time, sleep efficiency, and decrease sleep onset latency (how long it takes a person to fall asleep) [11]. The timing and the dosage amount also influences melatonin’s effectiveness, and sometimes this needs to be experimented with to find the sweet spot. And remember: more isn’t necessarily better.

What about for insomnia?

There are two things I would vouch melatonin for when it comes to insomnia: decreasing jet lag, and in shift workers.

1) Decreasing jet lag

• This is very intuitive based on the function of melatonin (to tell the body when it is night, and when it is day). This can be very effective, especially for people who travel across different time zones often for work. Having your body be able to sleep and be awake at the right times greatly improves quality of life, and helps make your travels seamless. It particularly effective when crossing five or more time zones, and dosing greater than 5mg seem to be no more effective [12]. (Repeat after me: more isn’t necessarily better)

2) Shift workers

• Decreased melatonin levels due to increased night time exposure to light has been one of the mechanisms proposed for increased cancer risk in shift workers [13]. Because this changes the circadian rhythm and all the downstream processes associated with that, it is no wonder that long term disruption would cause harm. Circadian rhythms influence metabolic processes, behaviours, social rhythms (e.g. feeding and working), and many hormones and genes. For example, there is evidence for misalignment of circadian rhythm and insulin resistance, as well as an increased risk of dyslipidemias with shift workers [14]. Melatonin has also shown to be effective in improving sleep onset latency and sleep efficiency in shift workers [15].

There is much more research on the effectiveness of melatonin for sleep disorders, particularly for reducing sleep onset latency in primary insomnia, for delayed sleep phase syndrome, and regulating sleep-wake patterns in blind patients [16]. The reason why I narrowed it down to just these two populations is because 1) a large part of the root cause in these populations is defined, and 2) sleep problems go way beyond melatonin dysregulation.

Many will take melatonin and complain that it did nothing for their sleep. This is because insomnia can be caused by adrenal exhaustion, your thyroid hormones, an overactive sympathetic nervous system, and even low blood sugar. So, while melatonin is not the be all and end all for problems with sleep, it can be pretty awesome for a lot of other things.

Keep an eye out for my next article, where I’ll be writing about when insomnia becomes a signal for deeper health issues. 

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