In brief: Melatonin is a natural hormone released in response to darkness that helps regulate circadian timing. It is not a universal sleeping pill. Its usefulness depends strongly on why someone is sleeping poorly and when melatonin is taken.[1]
What does melatonin do?
| Situation | Practical interpretation |
|---|---|
| Jet lag | Can support adjustment to a new time zone |
| Delayed sleep phase | Timing is crucial; not simply “at bedtime” |
| Chronic insomnia | CBT-I has a stronger long-term evidence base |
| Shift work | May help in some situations; evidence is limited |
NCCIH describes possible benefits especially for jet lag, delayed sleep-wake phase disorder and some other circadian problems.[1]
Why timing can matter more than dose
Melatonin acts as a timing signal. Depending on the goal, taking it too early, too late or simply at bedtime may be suboptimal. Higher doses do not automatically improve sleep and may prolong effects into the next day.
Light still matters
Bright evening light can delay natural melatonin release, while morning daylight helps stabilise the sleep-wake cycle. Melatonin works best in the context of regular timing and sensible light exposure; regular wake-up times and sleep hygiene should also be considered.
Side effects and uncertainties
Possible effects include daytime drowsiness, headache, dizziness and vivid dreams. NCCIH notes limited long-term safety data and particular caution during pregnancy, breastfeeding and in older adults.[1]
Product regulation also differs by country, and supplement content may not always match the label.
Interactions
Melatonin can interact with sedating medicines, alcohol, anticoagulants and other drugs. People taking regular medicines should check compatibility professionally.
When melatonin is not the real solution
Loud snoring with breathing pauses, severe daytime sleepiness, restless-legs symptoms, depression, pain or chronic insomnia need cause-focused assessment. See Sleep problems: causes, sleep hygiene and when to seek help.
FAQ
Is melatonin addictive?
Classic physical dependence like that seen with some sleeping medicines is not typical, but unnecessary long-term use should still be reviewed.
Is more melatonin better?
No. Higher doses do not automatically improve sleep and may increase next-day drowsiness.
Is melatonin suitable for every insomnia problem?
No. CBT-I is better supported for chronic insomnia.
Can melatonin help jet lag?
Yes, when timed appropriately it can support adjustment to a new time zone.
Conclusion
Melatonin is mainly a tool for biological timing. Indication, timing, dose and interactions matter more than simply taking a larger amount.
Sources
This article provides general information and does not replace individual medical advice.
