Melatonin - is it the answer for poor sleep?
You’re in bed.
Tossing and turning.
But you can’t get to sleep.
You remember someone saying something about melatonin.
“Gets me to sleep straight away! It’s genius! Everyone’s using it!”
Well, here is what we know about melatonin supplementation and whether you should take it…..
What is melatonin?
Popularly know as the ‘sleep hormone’ (more of that later!) melatonin is synthesised from serotonin via tryptophan primarily by the pineal gland, in the middle of the brain. Melatonin production is triggered by darkness and therefore peaks at night and is conversely suppressed by light making melatonin levels lowest during the day.
Yay, it makes you go to sleep!
That is what the marketing for melatonin supplements will tell you.
But, well, how do I say this?
No.
Oh. Right. Then what does melatonin do?
The research shows that melatonin plays an important role in regulating the physical, behavioural, and mental changes your body goes through in a 24 hour cycle, also known as your circadian rhythm. It’s involved in blood pressure and immune system regulation and the menstrual cycle amongst many others, but its best known role is its part in regulating your sleep/wake cycle.
Essentially, light or darkness travels through the eyes into the suprachiasmatic nucleus (SCN). Also known as the ‘master clock’, the SCN co-ordinates the roughly 24 hour cycle of rhythms that your body goes through (without the SCN, all this would, over time, desynchronise and we would all be a bit of a mess!). When there is darkness the SCN tells the pineal gland to secrete melatonin and times its release whilst melatonin feeds back to the SCN when to decrease it. Along with other bodily processes such as a drop in body temperature, melatonin essentially indicates to the body that it is time to sleep.
So, melatonin makes you go to sleep?
Not quite.
The term ‘sleep hormone’ can lead you believe that it does, but this is misleading. It doesn’t cause you to go to sleep, but it is correlated with certain aspects of sleep.
How do we know?
Well melatonin is produced not only in humans but all mammals. In nocturnal animals’ melatonin is still produced at night when they are most active – and it certainly doesn’t send them to sleep! It is produced at night but simply doesn’t send us to sleep immediately, taking up to 2 hours or so to be effective. As we age we produce less melatonin and yet clinical studies show that the effectiveness of melatonin supplementation in the elderly is questionable at best. And many studies have also shown that melatonin does not work to send you to sleep any better than placebo.
If you think it will send you to sleep, it will?
It’s maybe more helpful to think of it as a potential aid to sleep timing rather than as a sleeping pill.
Ok, melatonin helps us prepare for sleep. So, putting more melatonin in me will help me sleep better, yeah?
Melatonin supplementation has grown hugely in popularity in recent years form 0.4% to 2.1% from 1999 to 2018, with the amount taken doubling in the last ten years.
Does the research support it?
Firstly, all of the following comes with a caveat. There is a lack of Randomised Control Trials (RCTs) in general and the studies done are mostly short term. There are lots of differences across studies including variable dosages, short vs long term release protocols, pairing with and without behavioural changes and inconsistent formulations which make the true picture unclear.
But this is what we know right now.
Melatonin supplementation is generally correlated with certain aspects of better sleep, but as we found before it promotes it rather than causes it like a sleeping pill would. Many individual studies show that it may reduce sleep onset (the time it takes to get to sleep) by a little bit, ranging from around 5-30 minutes or so. A meta analysis from 2013 showed that on average people fell asleep 7 minutes faster and slept for 8 minutes longer, with a lot of individual variation, for melatonin supplementation compared to placebo. A 2018 umbrella review found benefits for sleep onset and total sleep time but could not agree on whether it was meaningful, in part due to the low-moderate quality of the papers. In 2020 a meta-analysis of 12 studies found melatonin supplementation slightly improved sleep onset but not sleep quality, also finding that supplementation (or other factors such as exercise or alternative or complimentary medicines) was no replacement, or even comparable, to CBTi as a treatment for insomnia.
As it’s tricky to know exactly the answer I am going to shamelessly paraphrase Russell Foster, Professor of Circadian Neuroscience at Oxford University at a talk of his I attended last year – “It’s going to help some people get to sleep maybe about 20 minutes faster than usual.”
But people say it helps jetlag?
Jetlag is linked to circadian disruption and deserves a blog of its own.
Given a little time, it sorts itself out.
Briefly for the purposes of this blog, much evidence comes from small scale studies. An influential and well-received 2002 paper examining 10 trials supporting melatonin for jet lag was later revised down to 4 trials and just 142 participants (a fact often completely ignored). Another well quoted 2015 paper analysing 4 studies with 232 participants found it was modestly more effective than placebo.
Despite the noise around this the evidence is scant and needs large scale studies. The studies we have also don’t pinpoint effective doses, there seems to be complexities around the timing of doses and side effects aren’t identified.
Rather you than me!
Ok. Nightshift work then!
Again, another topic that will get its own blog!
Night-shift work is another circadian rhythm disruptor, and again the evidence doesn’t support the use of melatonin to aid sleep. A 2014 review of 7 low quality studies found positively for melatonin, whilst another 2014 review of 5 different higher quality studies proved inconclusive (they favoured neither melatonin nor the control) and had small sample sizes.
What about melatonin for children?
It’s a good question. And before I start, I do not recommend just self administering melatonin to children (or adults) because you have heard from someone down the road that it might help.
Firstly, whilst melatonin is generally considered safe for short term across age ranges
we don’t really know how safe it is yet longer term
it may cause side effects like headaches and nausea and anxiety and impact blood pressure and more
it may adversely react with antidepressants, blood pressure drugs, diabetes medications, autoimmune drugs, other sleeping pills like Valium and more
there are concerns that long term use may affect puberty (although research here is lacking)
most studies are short term and the NHS advice is not to take it for longer than 13 weeks anyway
Secondly, if you are having trouble sleeping - you need to see someone to find out why.
If you just jump to a supplement – which may or may not have any effect – you are not going to understand why you are having the issue in the first place and this may lead to more serious long term health issues. CBTi is proven to be the most effective treatment for insomnia (and there are no side effects, less chance of relapse and better long term outcomes) so this is always the first stop.
Yes, yes, yes – is it ok for kids?
There is a real lack of evidence.
A 2020 meta-analysis of 34 RCTs in children and adults found that there was better evidence for the use of melatonin in children than adults around getting to sleep and total sleep time.
Acknowledging there are mixed results in trials the British Association for Psychopharmacology approved the short term use of melatonin for children (not adults) with autism spectrum disorder (ASD) in 2019 with a view to promote healthy sleeping habits.
Melatonin is sometimes prescribed by clinicians as part of a plan to help improve sleep in children with ADHD where it tries to off-set the wakefulness properties of prescribed stimulant medications. It is not currently clear if the sleep problems often associated with ADHD and ASD are just part of the ADHD and ASD picture or prompted by anxiety or behaviour.
Interestingly, a 2017 review of 62 studies found evidence that ADHD may be associated with a later chronotype (genetic tendency to want to go to bed later and get up later) and this may also be part of the picture. There is some evidence of melatonin’s efficacy from small, recent studies in 2019 and 2023. A 2020 review of the literature stated melatonin may have a beneficial effect for children getting to sleep but acknowledged it’s limitations around research groups, dosages, types of melatonin used and lack of understanding around side effects.
However, it is available when working with clinicians in the UK.
Should I supplement with melatonin?
Firstly, you should note that most people produce plenty of melatonin perfectly well, perfectly naturally. You can also increase your melatonin production naturally with good sleep habits.
You produce melatonin naturally throughout the night (peaking around 2-4am) and this helps you to stay asleep. However, whilst synthetic melatonin lasts about 4 to 5 hours there is no real consensus on this an it can be as wide as 2.5 - 10 hours. So whilst it may help some people fall asleep initially, supplementation may not help you stay asleep.
If you are taking it to stop you waking in the middle of the night?
Melatonin might not be effective.
Secondly taking it may mask other things that are interfering with your sleep and need to be dealt with, like lifestyle habits or stress management.
Come on Baz, get to the sexy supplements bit!
Okey dokey.
Whilst melatonin is naturally produced by us it is also created synthetically. You can buy them from the internet in all sorts of forms – tablets, teas, gummies and even patches.
The big problem?
These melatonin supplements are not regulated in America. In the UK and the EU melatonin is classed as a medicine, only available by prescription. The melatonin supplements you see plastered all over the internet? They are not regulated, the quality is not guaranteed, and nor are the contents.
A 2017 review of melatonin supplements that found 70% of those tested varied wildly from what they stated were in them with melatonin content ranging from -83% to +478%. Another US study published in 2023 found that of the 22 out of 25 supplements tested, the quantity of melatonin ranged from 74% - 347% of what was claimed. One didn’t contain any. Many have been found to contain serotonin which again has its adverse effects for some people.
Hence what you buy over the counter is very different from the ‘pure’ melatonin supplements you get by prescription.
I don’t care! My mate says I should take it. How much should I take?
The relevant dosage and timescale depend upon whom you talk to.
The NHS says adults and children should start with 2mg moving up to a maximum of 10 mg for a maximum of 13 weeks. WebMD states ‘melatonin has most often been used by adults in doses up to 8 mg by mouth daily for up to 6 months. In children, it's most often been used in doses up to 3 mg by mouth daily for up to 3 months.’ The Sleep Foundation says experts recommend starting with 1 mg or less and increasing if needed with most taking between 1 and 5 milligrams. A 2019 review of the clinical literature says between 1-6mg in older adults ‘seem to be effective’.
So - whom do you believe? How do you make that judgement?
Why does this matter?
Whilst a recent review concluded that high-dose studies appeared to have a ‘good safety profile’, the same study stated there is limited evidence.
We just don’t really know.
The aim here with a clinician is to find the lowest effective dose possible for you over the shortest possible time. And what concerns me is that whilst the general consensus is that you shouldn’t go beyond a maximum of 10mg at most, you can very easily buy 10mg and even 20mg ‘melatonin’ tablets online with the click of a button.
So. Baz! What’s the advice? Do we take it?
It is generally considered safe if taken in small doses for very short time periods.
But!!!
Think for a moment.
The potential is that you might get to sleep a very little quicker than you normally would using a supplement that has – exactly what in it?
And if you use it as a ‘first line of attack’ then you are not dealing with the underlying issues and are likely to get into bad sleep habits that make the situation worse.
And no, we don’t know it’s safety when taken over longer periods of time or at higher doses.
If you suffer from insomnia?
CBTi is the acknowledged first response. It is safe and has a proven record of success, and success that sustains itself after treatment.
If your sleep issues are more infrequent or just occasionally annoying?
Then doing the basics well and/or working with a sleep expert is going to be far more beneficial. There are lots of things you can do around sleep habits, stress management and understanding sleep itself that are going to work better for you.
And if that doesn’t work for you for some reason? THEN speak to a clinical professional about potentially looking at short term medications or supplements in conjunction with CBTi.
Unless there is an identified specific need to take it and you have tried consistently implementing well researched sleep habits to no avail?
I honestly don’t see the point.
p.s. this article has been researched and written by me, NOT by AI, although it has created the images for me. Hey, I never said I was perfect…….