Melatonin is often nicknamed the sleep hormone. Naturally produced by the brain as night falls, it has also become one of the best-selling supplements for people who struggle to fall asleep. But how well does it actually work?
In brief – Melatonin is a hormone released by the pineal gland after dark that signals to the body that night has come, helping to synchronize the internal clock. It is most useful for circadian rhythm problems such as jet lag, delayed sleep phase and shift work, with a more modest effect on chronic insomnia. Low doses of 0.5 to 2 mg, taken 30 to 60 minutes before bedtime, are usually as effective as higher doses and better tolerated. It works best alongside good sleep habits, regular hours, a dark cool bedroom, less evening light, rather than instead of them. Side effects are generally mild (morning drowsiness, headache, dizziness) but caution is advised for pregnant or breastfeeding women, people with epilepsy or asthma, and those on blood thinners or immunosuppressants.
What is melatonin?
Melatonin is a hormone released by the pineal gland in response to darkness. It signals to the body that night has arrived and that it is time to rest, helping to synchronize the internal clock. Natural production of this hormone declines with age, which partly explains why sleep problems become more common after age 50.
When is melatonin actually useful?
This supplement is not a classic sleeping pill: it mainly acts on the sleep-wake rhythm. It is particularly useful in specific situations:
- Jet lag, where it helps resynchronize the internal clock;
- Delayed sleep phase syndrome, common among teenagers and night owls;
- Night shift work or irregular schedules;
- Mild difficulty falling asleep, alongside good sleep hygiene;
- Older adults, whose natural secretion has declined.
What the science actually says
The available evidence is summarized by leading institutions: the National Center for Complementary and Integrative Health (NCCIH) notes that melatonin can help with jet lag and delayed sleep phase, with a more modest effect on chronic insomnia.
Research backs this up: see the studies on melatonin and insomnia and on melatonin and jet lag. Its benefit is real but narrow: it mainly reduces the time it takes to fall asleep, with a limited effect beyond that specific use.
In practice: using melatonin well
Melatonin works best alongside real sleep hygiene, not as a replacement for it. Combine it with our 9 keys to better sleep and our mental well-being strategies to ease evening stress. Find all our sleep coverage in the Sleep pillar.
Protocol: dose and timing
- A low dose is often enough: 0.5 to 2 mg, rather than high doses.
- 30 to 60 minutes before bedtime for an effect on sleep onset.
- For jet lag: at the destination’s bedtime, for a few days.
- In the dark: turn off screens, since light inhibits natural melatonin.
- For a limited period, reassessing its usefulness regularly with a professional.
| Situation | Typical dose | Best time to take it |
|---|---|---|
| Jet lag | 0.5 to 2 mg | At the destination’s bedtime, for a few days |
| Mild difficulty falling asleep | 0.5 to 2 mg | 30 to 60 minutes before bed |
| Shift work | 0.5 to 2 mg | Before the planned sleep period |
| Delayed sleep phase | 0.5 to 2 mg | 30 to 60 minutes before the target bedtime |
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Safety and side effects
At usual doses and over short periods, melatonin is generally well tolerated. Possible side effects remain mild: morning drowsiness, headache, dizziness or digestive upset. Caution is warranted for certain people, though: pregnant or breastfeeding women, those with epilepsy or asthma, and people on blood thinners or immunosuppressants. Medical advice is recommended before use in these situations.
Melatonin can also interact with several medications. It is best treated as a supplement to use thoughtfully and temporarily, not as a habit taken lightly over the long term.
Melatonin or sleep hygiene?
No supplement can permanently make up for poor sleep hygiene. Before turning to melatonin, it is essential to get the basics right: regular hours, a cool dark bedroom, no screens in the evening, less caffeine after midday, and exposure to daylight in the morning. These steps strengthen the body’s natural hormone production, often more effectively than a pill.
That is where melatonin finds its proper place: an occasional boost, useful in specific situations, alongside rather than instead of a lifestyle that supports sleep.
Immediate release or prolonged release: which form to choose
Not all formulations suit every problem. The immediate-release form acts quickly and works well for difficulty falling asleep: it is taken shortly before bed to shorten the time needed to fall asleep. The prolonged-release form releases the hormone over several hours and targets nighttime awakenings or fragmented sleep, which become more common with age.
The right choice depends on the main symptom. When in doubt, a pharmacist or doctor can point to the right form and dose rather than guessing. A low dose taken at the right time is often more effective than a high dose taken at the wrong one.
Melatonin and children: caution is essential
Melatonin is sometimes offered to children, particularly for sleep problems linked to certain neurodevelopmental conditions. But pediatric use should never be decided alone: it requires a prescription and medical follow-up. A child’s sleep first depends on lifestyle basics, regular hours, a bedtime routine, fewer screens in the evening, before any supplementation is considered.
Self-medicating a child is therefore to be avoided. What may seem harmless for an adult calls for specific evaluation when the body in question is still developing.
Boosting natural production
Before turning to a supplement, there is a lot that can be done to support the body’s natural production of the sleep hormone:
- Get daylight exposure in the morning, which sets the internal clock and prepares the evening release;
- Reduce evening light, especially the blue light from screens, which slows production;
- Sleep in complete darkness, essential for optimal secretion;
- Keep regular hours, including on weekends;
- Avoid caffeine and alcohol late in the day.
These steps, detailed in our 9 keys to better sleep, strengthen the sleep-wake rhythm without a single pill and should be the first step to try.
Interactions and precautions to know
Even at low over-the-counter doses, this supplement is not harmless for everyone. It can interact with blood thinners, diabetes medications, immunosuppressants, certain anti-epileptic drugs and medications acting on the nervous system. People with autoimmune conditions, epilepsy or depression should seek medical advice before taking it. It is also best to avoid driving right after taking it, given the drowsiness it can cause. If sleep problems persist beyond a few weeks, a consultation is warranted to find the cause: a condition such as sleep apnea can hide behind stubborn fatigue.
Jet lag: the detailed protocol
Jet lag is where melatonin shows its clearest benefit. When traveling east (the hardest direction to adjust to), it is taken at the destination’s bedtime for the first few days after arrival. Traveling west, the need is smaller. Light exposure strengthens the effect: getting morning sunlight at the destination helps the internal clock reset faster. A low dose is usually enough; there is no benefit to taking more milligrams. Combined with good hydration and meal times aligned with the new time zone, this strategy meaningfully shortens jet lag and the fatigue of the first few days.
Choosing a good supplement
Not all products are equal. Quality, actual dosage and formulation (immediate or prolonged release) vary widely between brands. It is best to choose supplements from a reliable source, with a clearly stated dose, and to start with the lowest amount. In France, above a certain dose, melatonin is classified as a medication and requires a prescription; rules vary from one country to another, so check what applies where you live. If in doubt about a product or dosage, a pharmacist remains the best source of advice. Finally, a supplement never fixes sleep undermined by poor habits on its own: it works as a support to a well-kept lifestyle.
Frequently asked questions
Is melatonin addictive?
No, it does not cause physical dependence the way some sleeping pills do. It does not act on the same brain circuits. A person can, however, develop a psychological habit around taking it, so occasional use is best.
What dose of melatonin should I take?
A low dose, between 0.5 and 2 mg, is often just as effective as a high dose and better tolerated. It is best to start low and discuss it with a pharmacist or doctor.
When should I take melatonin?
Generally 30 to 60 minutes before bedtime to help you fall asleep. For jet lag, timing is adjusted to the destination’s bedtime.
Is melatonin effective against insomnia?
Its effect on chronic insomnia is modest. It is mainly useful for rhythm disorders (jet lag, delayed sleep phase) and for slightly reducing the time it takes to fall asleep.
Medical disclaimer. The information provided here is for informational purposes only and does not constitute medical advice. It does not replace a consultation. Ask a healthcare professional before changing your diet, taking dietary supplements or starting a new practice, especially if you have a medical condition, are pregnant or are under treatment. Dietary supplements do not replace a balanced diet or medical follow-up.
