🌙 Melatonin Guide
Melatonin Dosage
and Timing
What research says about how much melatonin people take, when timing matters most, and why you should talk to a doctor before you start.
What Melatonin Does — and Doesn’t Do
Melatonin is a timing signal, not a sleeping pill. Understanding that explains most of the dosage and timing questions.
Your brain releases melatonin in the evening as daylight fades. It tells the body that biological night has begun. Bright light, especially in the evening, suppresses it. Learn more about this daily cycle in Circadian Rhythm Explained.
Supplemental melatonin works in two ways. It can make some people slightly sleepier in the short term, and it can shift the body clock earlier or later depending on when it is taken. The second effect is why timing matters so much. On average, its effect on simply falling asleep is modest: a meta-analysis of trials in primary sleep disorders found it shortened the time to fall asleep by about 7 minutes and added about 8 minutes of total sleep.[2]
Melatonin is sold as a supplement in some countries and is a prescription medicine in others. Rules, products and recommended uses vary. This guide is general education based on published research. It is not dosing advice, and it is not a substitute for advice from a doctor or pharmacist who knows your health and medicines.
Melatonin: Timing Matters
What studies found for different goals — general education, not dosing advice
⏰ BY GOAL
0.5 mg gave the biggest advance when taken in the afternoon, 2–4 h before the body’s own melatonin rise.
Doses of 0.5–5 mg near local bedtime were similarly effective; above 5 mg was no better.
Added about 24 minutes of daytime sleep (low-quality evidence).
📊 REALITY CHECK
Average reduction in time to fall asleep in primary sleep disorders.
Range of actual melatonin content versus the label in tested supplements.
Melatonin Dosage: What the Research Shows
More is not necessarily better. Studies have used a wide range of doses, and higher doses do not reliably work better.
Research has tested doses from well under 1 mg to 10 mg. A few findings stand out:
Low doses can shift the clock. In a study comparing 0.5 mg and 3 mg taken once a day for three days, both doses shifted the body clock. The best time to take each dose differed, and the 0.5 mg dose produced its largest advance when taken in the afternoon.[1]
For jet lag, a ceiling appears. A Cochrane review found that doses between 0.5 mg and 5 mg were similarly effective, though people fell asleep faster and slept better after 5 mg than 0.5 mg. Doses above 5 mg appeared to be no more effective.[3]
For shift work, no clear dose effect. A Cochrane review of trials using 1–10 mg after night shifts did not find a dose-response effect.[6]
Labels may not match the bottle. A study of melatonin supplements found the actual content ranged from 83% less to 478% more than the label stated, and more than 71% of products were not within 10% of their label claim.[4] This is one more reason to choose products carefully and get advice before using them.
| Goal | What studies used | Timing in studies | Evidence |
|---|---|---|---|
| Shift the body clock earlier | 0.5 mg and 3 mg[1] | Afternoon or early evening, hours before natural melatonin rise | Controlled lab study |
| Jet lag (eastward or 5+ time zones) | 0.5–5 mg[3] | Near target bedtime at destination | Cochrane review |
| Daytime sleep after night shift | 1–10 mg[6] | Before daytime sleep | Low quality |
| Delayed sleep–wake phase disorder | Guideline-based, prescribed[5] | Timed by a clinician | Clinical guideline |
| General trouble falling asleep | Various[2] | Before bed | Modest average effect |
Melatonin Timing by Goal
The same pill can move your clock earlier, later or not at all, depending on when you take it.
- 1
To fall asleep earlier (night owl schedule)
Research on the phase response curve shows melatonin taken in the afternoon or early evening — hours before your body’s own melatonin rise — produces the biggest shift earlier.[1] Pair it with morning light and a fixed wake time, as described in our guide to resetting your circadian rhythm. Delayed sleep–wake phase disorder is a diagnosis for a doctor to make; a clinical guideline supports timed melatonin for it.[5]
- 2
For jet lag
Trials typically gave melatonin close to the target bedtime at the destination, mainly for eastward flights and trips crossing 5 or more time zones. The review also warned that taking it at the wrong time can delay adaptation.[3] Plan light and sleep timing with the Jet Lag Recovery Calculator.
- 3
For night-shift workers
Trials gave melatonin before daytime sleep after a night shift, adding about 24 minutes of daytime sleep on average, but the evidence quality was low.[6] See our Shift Worker Sleep Guide and the Shift Work Sleep Planner.
- 4
For general trouble sleeping
For occasional poor sleep, habits usually do more than a supplement. Start with our sleep hygiene checklist and techniques for falling asleep fast.
Who Should Be Careful With Melatonin
Melatonin is widely used, but it is not right for everyone.
Talk to a doctor or pharmacist before using melatonin if any of the following apply:
Children and teens
Sleep problems in children often have behavioural or medical causes that need assessment. Do not give melatonin without medical advice.
Pregnancy and breastfeeding
There is limited research on safety. Ask your doctor before using it.
Other medicines
If you take any regular medicine, ask a doctor or pharmacist before trying melatonin, since it may not mix well with some medicines.
Next-day drowsiness
Some people feel groggy after taking it. Avoid driving or operating machinery if you feel sleepy.
Ongoing sleep problems
Long-term insomnia, loud snoring or extreme daytime sleepiness need a medical assessment, not self-treatment.
Product quality
Content can differ widely from the label.[4] Ask a pharmacist about reliable products.
This guide is for general education only. It is not a diagnosis, a treatment plan or dosing advice, and it does not replace advice from a qualified healthcare professional.
🌙 Plan Your Sleep Timing
Work out when your body clock is ready for sleep.
Frequently Asked Questions About Melatonin Dosage
There is no single right dose, and you should ask a doctor or pharmacist before starting. Studies have used a range of doses, from well under 1 mg up to 10 mg, and higher doses have not reliably worked better. For jet lag, a Cochrane review found 0.5–5 mg similarly effective.
It depends on the goal. To shift the body clock earlier, research shows the biggest effect when it is taken hours before the body’s own evening melatonin rise. For jet lag, trials usually gave it near the target bedtime at the destination.
Long-term nightly use has not been well studied in many groups. If you feel you need it regularly, speak to a doctor to look for the underlying cause of your sleep problem.
Only with medical advice. Children’s sleep problems often need a different approach, and doses and products should be guided by a doctor.
Common reasons include taking it at the wrong time, bright evening light cancelling its signal, a product that does not match its label, or a sleep problem that melatonin does not treat.
Not reliably. For jet lag, doses above 5 mg appeared no more effective, and a shift-work review found no clear dose-response effect.
Related Sleep Resources
Put this guide into practice with our free calculators and in-depth guides.
References & Further Reading
- Burgess HJ, et al. (2010). Human phase response curves to three days of daily melatonin: 0.5 mg versus 3.0 mg. J Clin Endocrinol Metab, 95(7), 3325–3331. PubMed 20410229 · doi:10.1210/jc.2009-2590
- Ferracioli-Oda E, Qawasmi A, Bloch MH. (2013). Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS One, 8(5), e63773. PubMed 23691095 · doi:10.1371/journal.pone.0063773
- Herxheimer A, Petrie KJ. (2002). Melatonin for the prevention and treatment of jet lag. Cochrane Database of Systematic Reviews, (2), CD001520. PubMed 12076414 · doi:10.1002/14651858.CD001520
- Erland LA, Saxena PK. (2017). Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content. J Clin Sleep Med, 13(2), 275–281. PubMed 27855744 · doi:10.5664/jcsm.6462
- Auger RR, et al. (2015). Clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders. J Clin Sleep Med, 11(10), 1199–1236. PubMed 26414986 · doi:10.5664/jcsm.5100
- Liira J, et al. (2014). Pharmacological interventions for sleepiness and sleep disturbances caused by shift work. Cochrane Database of Systematic Reviews, (8), CD009776. PubMed 25113164 · doi:10.1002/14651858.CD009776.pub2