Melatonin: You're Probably Taking 5–10x Too Much
Melatonin is the most-purchased sleep supplement in the world, and most people take it wrong. Not dangerously wrong — melatonin is remarkably safe short-term — but inefficiently wrong: doses several times larger than the research supports, taken at times that don’t match the hormone’s actual job.
What melatonin actually does
Melatonin doesn’t sedate you. Your pineal gland releases it in the evening as a biological time signal: “night is starting.” It shifts the timing of your sleep — which is why it shines for jet lag and schedule problems and underwhelms for garden-variety insomnia.
That mechanism explains everything else in this article.
The dose problem
Jet-lag and shift-work trials consistently find benefits at 0.5–1 mg. Above that, effects on sleep timing don’t meaningfully increase — but next-morning grogginess does.
Now check your bottle: it probably says 5 mg or 10 mg. US melatonin is sold as a dietary supplement, so doses are set by marketing departments, not pharmacology. Analyses of melatonin products have found actual content ranging from ~-80% to +450% of the label claim — another reason third-party tested brands matter here more than usual.
Practical fix: buy 1 mg tablets (or liquid for titrating to 0.5 mg). More is not stronger; it’s just more.
The timing problem
Because melatonin is a clock signal, when you take it outranks how much:
| Situation | Sensible approach |
|---|---|
| Falling asleep too late (delayed rhythm) | 0.5–1 mg, 3–4 hours before desired bedtime |
| Eastbound jet lag | 0.5–1 mg at local target bedtime, starting the evening before travel |
| Night-shift work | Strategically, per a doctor’s guidance — this one’s genuinely tricky |
| Ordinary “can’t sleep” stress insomnia | Modest evidence; sleep-hygiene work first |
The common habit — popping 10 mg at midnight after failing to fall asleep — is the least useful possible deployment: too much, too late, for the wrong problem.
Safety notes
- Short-term use in adults is well tolerated. Headaches and morning fog at high doses are the main complaints.
- Kids and teens: growing evidence of real use, but melatonin in children should involve a pediatrician, not a gummy brand’s Instagram ads.
- Interactions: blood thinners (notably warfarin), immunosuppressants, diabetes medication, and contraceptives can interact — pharmacist check if any apply.
- Pregnancy/nursing: insufficient data; skip it.
Bottom line
If you take melatonin, take 0.5–1 mg, timed for what you’re fixing — earlier in the evening for a late-shifted body clock, at target bedtime for eastbound travel. If it “never worked” at 10 mg, the dose wasn’t the missing ingredient; the timing and the job description were.
For ordinary stress-related sleep trouble, the better-studied basics elsewhere on this site — magnesium glycinate, ashwagandha, and boring sleep-schedule discipline — earn their place first.
Low-dose melatonin 0.5–1 mg (via iHerb)
Look for 0.5 mg or 1 mg tablets — the doses used in actual trials. Gummy megadoses are the marketing, not the medicine.
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