Melatonin dosage: why less is often enough
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A 0.3 mg tablet is enough to bring your blood to about the level your own melatonin reaches on a normal night. Bigger doses help a little more with falling asleep, up to about 4 mg in a 2024 analysis of 26 trials, and jet lag trials found nothing extra above 5 mg. Start at 0.5 to 1 mg. 3 mg is plenty for most people, and 5 mg is the top.
Most bottles in a US store hold much more than that, and a 10 mg gummy is easy to find. Its peak is about 33 times a normal night’s, and most of what it adds is time spent in your blood.
What we’d do
Start with 0.5 to 1 mg at the right hour, for two weeks. If your own nights show nothing and the hour is right, step up to 3 mg. Stop at 5 mg. If you’re 60 or over, start at 0.3 to 0.5 mg. If you wake up groggy, the dose was too big or too late, so cut it or take it earlier.
The smallest dose of all is none. If you want to and you can, give your own melatonin two weeks of morning daylight, dim evenings and a dark bedroom first, and how to increase melatonin naturally shows how.
If you remember three things
- 0.3 mg matches a normal night. Everything above it is more than your brain makes.
- The clock doesn’t need more. 0.5 mg moved it as far as 3 mg, each at its best hour.
- Extra milligrams buy hours. A tablet halves about every 54 minutes, so each doubling keeps it up about an hour longer.
Isn’t a bigger dose stronger?
For a lot of drugs it is. Two painkillers do more than one, and that’s the habit people bring to the melatonin shelf.
Melatonin is a signal your brain already sends at a small level every night. In a 1994 MIT study, 20 men took doses from 0.1 to 10 mg at noon. The amount in their blood rose in step with the dose, and the 0.1 and 0.3 mg doses gave peaks inside the normal range for a night. Every dose made them sleepier than a placebo, even 0.1 mg.
Past a normal night’s level, the trials found the effect grows slowly and then stops. What keeps growing is how long the dose lasts, because a bigger dose takes more time to clear.
A simple way to picture it
It’s like making an announcement in a quiet room. A normal voice reaches everyone. Shouting reaches the same people, and then it echoes off the walls for the rest of the evening.
A small dose is the normal voice. A 10 mg gummy is the shout, and the echo is still going when your alarm goes off.
What did the dose trials find?
Older adults, three doses
30 adults over 50, a week on each dose. Zhdanova and others at MIT, 2001
0.3 mg, 30 minutes before bed, restored sleep efficiency in the poor sleepers and raised their blood melatonin to normal. 3 mg also improved sleep, but it lowered body temperature and kept melatonin up into daylight. The good sleepers weren’t affected by any dose.
Small, and one week per dose.
The clock, two doses
34 adults aged 18 to 42 on 0.5 mg in a lab, against the same team’s earlier 3 mg study. Burgess and others, 2010
Taken at each dose’s own best hour, 0.5 mg and 3 mg moved the body clock about the same amount.
Three days in dim light, so real life may be slower.
Jet lag, many doses
10 trials in passengers, crew and soldiers. Cochrane review, 2002
0.5 to 5 mg worked about equally, except that people fell asleep faster and slept better after 5 mg than 0.5 mg. Doses above 5 mg did no better.
Ten trials from before 2002, nine of them good enough to count.
Falling asleep, many doses
26 trials, 1,689 observations. Cruz-Sanabria and others, 2024
The effect on falling asleep and total sleep grew with the dose and peaked at about 4 mg a day.
The trials mixed timings, doses and kinds of people.
A 2013 analysis of 19 trials agreed that higher doses and longer trials showed bigger effects, though the average gain was still about 7 minutes faster to sleep.
How long does each dose stay above your own?
A tablet peaks about 40 minutes after you swallow it, then halves about every 54 minutes. Taken at 10:30pm, here’s when each dose drops back under your own night’s peak. The later time in each range uses a slower halving of 1.5 hours, which we assume for people whose melatonin lingers, like many older adults.
| Dose | Peak, times a normal night | Back under your own night’s peak | Tart cherries with the same melatonin |
|---|---|---|---|
| 0.3 mg | about 1 | level with it | 49 lb |
| 0.5 mg | about 1.7 | 11:50pm to 12:15am | 82 lb |
| 1 mg | about 3 | 12:45 to 1:45am | 164 lb |
| 3 mg | about 10 | 2:10 to 4:10am | 491 lb |
| 5 mg | about 17 | 2:50 to 5:15am | 819 lb |
| 10 mg | about 33 | 3:45 to 6:45am | 1,640 lb |
| 20 mg | about 67 | 4:40 to 8:15am | 3,280 lb |
The cherry column uses Montmorency tart cherries, which hold about 13.46 nanograms of melatonin per gram. The times come from one simple model and real people vary a lot. In the 2016 study behind the 54 minutes, the same 10 mg tablet peaked more than three times higher in some men than in others.
One night, three curves
- Your own night, from 9:35pm
- 0.5 mg at 10:30pm, back by 11:50pm to 12:15am
- 10 mg at 10:30pm, back by 3:45 to 6:45am
The night curve explains the halving, and your dose across the night draws it against your own alarm.
Why not start at 4 mg, if that’s where the effect peaked?
The sceptic says
The biggest review says 4 mg works best. Starting at half a milligram just wastes two weeks.
The reply
The extra is small and the cost is hours. The 4 mg peak is where the curve tops out across 26 trials, and the whole effect is a few minutes of falling asleep. A 4 mg tablet is still about 13 times a normal night at its peak and stays up into the early morning. For moving your clock, 0.5 mg did the full job. Start low at the right hour, and step up if your own two weeks say it isn’t enough.
How do you find your dose?
- Get the hour right first. The melatonin window gives it for your job. A big dose at the wrong hour does less than a small one at the right hour.
- Start at 0.5 to 1 mg. 0.3 to 0.5 mg if you’re 60 or over. 0.3 mg is the same as 300 mcg, and 0.5 mg is 500 mcg.
- Run it for two weeks against nights off. The two-week test compares them with your normal night-to-night swing.
- Step up only if nothing changed. Next 1 mg, then 3 mg. Stop at 5 mg.
- Step down if you’re groggy. Daytime sleepiness was the most common side effect across 37 trials, reported by 1.66 percent of people. It usually means the dose was too big or too late.
What if I take gummies?
Then you don’t really know your dose. In a 2023 lab test of 25 US melatonin gummies, 22 missed their label, holding from 74 to 347 percent of the stated amount, and one had no melatonin at all. Most held 1.2 to 1.7 times the label. A 5 mg gummy might hold anywhere from about 3.7 to 17 mg, most likely 6 to 8.5 mg. What’s really in a US bottle has the rest.
Why do older adults need less?
The 2001 MIT study is the one done in people over 50, and 0.3 mg was the dose that restored their sleep while 3 mg lingered into the next day. The US National Center for Complementary and Integrative Health says melatonin may stay active longer in older people and cause daytime drowsiness. Start at 0.3 to 0.5 mg, and take it well before bed so it’s gone by morning.
Don’t drive after a dose.
11 sources
- Dollins AB and others, Effect of inducing nocturnal serum melatonin concentrations in daytime on sleep, mood, body temperature, and performance, PNAS, 1994pubmed.ncbi.nlm.nih.gov
- Zhdanova IV and others, Melatonin treatment for age-related insomnia, Journal of Clinical Endocrinology and Metabolism, 2001pubmed.ncbi.nlm.nih.gov
- Burgess HJ, Revell VL, Molina TA, Eastman CI, Human phase response curves to three days of daily melatonin: 0.5 mg versus 3.0 mg, Journal of Clinical Endocrinology and Metabolism, 2010pubmed.ncbi.nlm.nih.gov
- Herxheimer A, Petrie KJ, Melatonin for the prevention and treatment of jet lag, Cochrane Database of Systematic Reviews, 2002pubmed.ncbi.nlm.nih.gov
- Cruz-Sanabria F and others, Optimizing the time and dose of melatonin as a sleep-promoting drug: a systematic review of randomized controlled trials and dose-response meta-analysis, Journal of Pineal Research, 2024pubmed.ncbi.nlm.nih.gov
- Ferracioli-Oda E, Qawasmi A, Bloch MH, Meta-analysis: melatonin for the treatment of primary sleep disorders, PLoS One, 2013pubmed.ncbi.nlm.nih.gov
- Andersen LP and others, Pharmacokinetics of oral and intravenous melatonin in healthy volunteers, BMC Pharmacology and Toxicology, 2016pubmed.ncbi.nlm.nih.gov
- Cohen PA and others, Quantity of melatonin and CBD in melatonin gummies sold in the US, JAMA, 2023pubmed.ncbi.nlm.nih.gov
- Burkhardt S and others, Detection and quantification of the antioxidant melatonin in Montmorency and Balaton tart cherries, Journal of Agricultural and Food Chemistry, 2001pubmed.ncbi.nlm.nih.gov
- Besag FMC and others, Adverse events associated with melatonin for the treatment of primary or secondary sleep disorders: a systematic review, CNS Drugs, 2019pubmed.ncbi.nlm.nih.gov
- National Center for Complementary and Integrative Health, Melatonin: What You Need To Know, last updated May 2024nccih.nih.gov
