Melatonin · Strong evidence
What melatonin is for and how much to take
The short answer. Melatonin is not a sleeping pill: it is the hormone the body uses to signal that it is night. It mainly works by bringing forward the time you feel sleepy, not by knocking you out. EU regulation authorises the claim about reducing the time it takes to fall asleep at 1 mg per serving, and the meta-analysis on sleep disorders finds real but modest effects. A higher dose is not a bigger effect.
Several meta-analyses or position stands from scientific societies agree that there is an effect. No figure on this page is attributed to a specific product: the effect belongs to the ingredient and every number carries its source next to it.
01 What it does and how much
Each row is a measured effect, with the figure the study gives and the source number. Where the evidence gives no figure, the column says so instead of making up a percentage.
| Effect | How much | Detail |
|---|---|---|
| Dose of the EU-authorised claim | 1 mg before bed | It is the legal condition of use to be able to say it reduces the time needed to fall asleep. 5 or 10 mg tubs are not better dosed: they are worse. [1] |
| Time to fall asleep | a few minutes less | The meta-analysis of primary sleep disorders finds a small but consistent reduction in latency. Useful, not spectacular. [2] |
| Total sleep time | slightly longer | Also small. Melatonin shifts the clock; it does not add hours on its own. [2] |
| Jet lag and shift work | its best case | When the problem is that the internal clock is on another time, melatonin does exactly what it is good at: moving it. [2] |
02 How to take it
- Dose. 1 mg. Going up to 3, 5 or 10 mg does not improve the effect and increases grogginess the next day.
- When. 30 to 60 minutes before bed. For jet lag, timed to the destination’s bedtime.
- How long before you notice it. It works that same night.
Details that change the result
- Light from screens and ceiling lamps suppresses your own melatonin. Taking a milligram and leaving the light on is working against the tub.
- Prolonged-release formats aim to sustain it after the peak; regular ones target latency. They are not interchangeable.
- It does not create physical dependence like hypnotics, but it does not fix a bad sleep habit either.
- In Spain, presentations above 1.9 mg per dose are medicines; the food supplement stays below that.
03 When it makes sense and when it does not
Worth it if
- Jet lag from travel: its clearest indication.
- Rotating shifts or delayed phase (you fall asleep very late and have to get up early).
- Occasional weeks of disrupted sleep, while habits get back on track.
Not worth it if
- As a sleeping pill for persistent insomnia: that needs a doctor.
- At 5 or 10 mg thinking a higher dose works better.
- In children, pregnancy or with long-term medication without asking.
04 Sources
Every figure above comes from here. They are position stands from scientific societies, meta-analyses and peer-reviewed reviews: if a claim cannot hang from one of these lines, it is not on the page. References are cited in their original form.
- Reglamento (UE) 432/2012 de la Comision: lista de declaraciones autorizadas. La melatonina contribuye a disminuir el tiempo necesario para conciliar el sueno; condicion de uso: 1 mg por porcion, poco antes de acostarse. https://eur-lex.europa.eu/legal-content/ES/TXT/?uri=CELEX%3A32012R0432
- Ferracioli-Oda E, Qawasmi A, Bloch MH. Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS One. 2013;8(5):e63773. Reduccion de la latencia del sueno y aumento del tiempo total de sueno, de magnitud pequena. doi:10.1371/journal.pone.0063773
This is not medical advice. It is what some studies say about an ingredient, not a protocol for you. With an illness, medication or pregnancy involved, the decision belongs to a healthcare professional who knows you.
Questions about melatonin
Answered with the data on this page
- How much melatonin should you take?
- 1 mg. It is the amount at which EU regulation allows saying it reduces the time needed to fall asleep, taken shortly before bed. The 5 or 10 mg doses you see around do not work better and make waking up groggy more likely.
- Is melatonin a sleeping pill?
- No. It is the hormone the body uses to signal night-time, so its effect is to bring forward the moment sleep arrives, not to knock you out. The meta-analysis finds somewhat shorter time to fall asleep and somewhat longer total sleep: real, modest effects, very different from a hypnotic.
- Is it addictive?
- It does not cause the physical dependence of classic hypnotics or the rebound effect linked to them. What it can create is a habit dependence: if the sleep problem comes from schedules, screens or stress, the tub covers it up while the cause remains.
- Does it help with jet lag?
- It is its best use case. When the problem is that your internal clock is in another time zone, taking it at the destination’s bedtime helps shift it. It is exactly what melatonin is good at: moving the clock, not forcing sleep.
And now, which to buy
Prices, kept apart from the evidence
This page explains what melatonin does and deliberately names no brand. The comparison is the other half: 116 products from 9 stores from €0.023 per capsule, sorted by price and by how verifiable their certification is.
Other guides
What each supplement does, with its sources