Melatonin has become the reflex: the thing you reach for after a run of bad nights, half because a friend swears by it and half because it is there on the shelf, promising to fix something. It is worth knowing what it actually does before you decide it is the answer.

We have no quarrel with the pill. For some people, in some situations, it has a real and specific use. But the story most of us have absorbed — melatonin as a natural sleeping pill — sits some way from what the research describes.

What melatonin actually is

Melatonin is not a sedative; it does not knock you out the way a sleeping tablet does. It is a timing signal, a hormone the pineal gland releases as the evening comes on, telling the body that night has arrived and the internal clock can begin its wind-down. It keeps the hour. Reviews do describe a mild sleepiness — and a small drop in body temperature — alongside that timing role, but the falling asleep is largely left to you.1

That distinction explains the pattern in the research. Melatonin appears to do most for problems of timing: jet lag, or a body clock that has drifted too late. It does rather less for the ordinary experience of lying awake with a busy mind, which is a matter of arousal rather than scheduling.

What the evidence really shows

A pooled analysis of nineteen studies of melatonin for primary sleep problems found a benefit, and a modest one: on average, the time taken to fall asleep shortened by about seven minutes and total sleep lengthened by around eight.2 Measurable, then, and a good deal smaller than most people expect from something they think of as a sleeping pill.

The major clinical guidelines are cautious for that reason. The American Academy of Sleep Medicine, reviewing the evidence, did not recommend melatonin for chronic insomnia; it judged the benefit too weak to endorse.3 The American College of Physicians puts something else first altogether: a course of behavioural change, cognitive behavioural therapy for insomnia.4

Melatonin tells the body when it is night. Whether the mind agrees to go quiet is a separate question, and a separate kind of work.

What the body already does for free

Your body makes its own melatonin, on its own schedule, and the release is remarkably sensitive to what is going on around you. Light most of all: ordinary room light in the evening is enough to suppress it, while dimness lets it rise.5 The blue-rich light of a screen read close to bedtime seems to work the same way.6 Temperature belongs to the same evening pattern, though the arrow runs the other way round from the way it is usually told: it is the rise in melatonin that comes with a slight fall in core temperature, rather than a cooling body that summons the hormone. The warm bath an hour or two before bed still has a plausible logic to it, only a plainer one — warmth draws blood towards the skin of the hands and feet, and the heat shed there appears to hasten the drop in core temperature that tends to accompany the onset of sleep. The warmth is not the point; the cooling that follows it is.

None of that requires a capsule. It asks only that the last hour of the day be allowed to feel like the last hour of the day.

Why the reflex can work against you

There is a subtler cost to it, too. Reaching for melatonin frames the problem as a chemical deficit to be topped up, when for a good many people, on a good many nights, what is missing is any signal to the nervous system that the day is over. Where those signals are attended to, the research suggests the body’s own timing is given rather more room to do its work.

Where the evidence points instead

If you want to give your own melatonin the best chance to do its job, these are the levers with the least hype and the most behind them:

  1. Dim the light before you dim yourself. Lower the lamps and put the bright screens down thirty to sixty minutes before bed. Nobody need be disciplined about it. You are only getting out of the hormone’s way.
  2. Keep the hour consistent. A body clock takes to a regular bedtime, and just as much to a regular wake time, weekends included.
  3. Let the room be cool. A slightly cool bedroom works with the body’s own temperature drop rather than against it.
  4. Lengthen the out-breath. A few minutes of slower breathing, the exhale longer than the inhale, is associated with a settling of the body’s alarm system, which is the part no tablet reaches. We wrote about it in The Longer Exhale.
  5. Give the mind somewhere else to be. A worried mind at 3am is rarely a chemistry problem. More often it is an old alarm doing its job too well, which is the subject of The Sabre-Tooth at 3am.

What we’re building from this

Mythrae’s sleep audio is not a substitute for any of the above, and it adds no chemistry. It is simply something undemanding for the attention to rest on while the body’s own signals come round in their own time. Nothing to swallow, nothing to time, no screen glowing in the dark.

That is the posture of the house. We would sooner hand the body back the conditions it already knows what to do with than try to talk over it.

A note. This essay is general education, not medical advice. Melatonin is a hormone with real uses — and, for some people and some conditions, real reasons to avoid it. If your sleep is a persistent problem, or before starting or stopping any supplement, speak to a pharmacist or clinician. Mythrae does not provide medical advice.

References

  1. Arendt, J. & Skene, D. J. (2005). Melatonin as a chronobiotic. Sleep Medicine Reviews, 9(1), 25–39.
  2. Ferracioli-Oda, E., Qawasmi, A. & Bloch, M. H. (2013). Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS ONE, 8(5), e63773.
  3. Sateia, M. J., Buysse, D. J., Krystal, A. D., Neubauer, D. N. & Heald, J. L. (2017). Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults. Journal of Clinical Sleep Medicine, 13(2), 307–349.
  4. Qaseem, A., Kansagara, D., Forciea, M. A., Cooke, M. & Denberg, T. D. (2016). Management of chronic insomnia disorder in adults: a clinical practice guideline from the American College of Physicians. Annals of Internal Medicine, 165(2), 125–133.
  5. Gooley, J. J., Chamberlain, K., Smith, K. A. et al. (2011). Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humans. Journal of Clinical Endocrinology & Metabolism, 96(3), E463–E472.
  6. Chang, A. M., Aeschbach, D., Duffy, J. F. & Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences, 112(4), 1232–1237.

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