Melatonin studies, tips and resources
Every tip and study on this site, each in one line you can pass on. Tap Copy and it goes in a message with its link.
Tips to pass on
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If you can, help your own melatonin first, with daylight soon after waking, lamps in the evening and a dark bedroom.
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Take melatonin 1 to 3 hours before bed. In a 2024 analysis of 26 trials, earlier doses did better.
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Start at 0.5 to 1 mg. 3 mg is plenty for most people, and 5 mg is the top.
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A 10 mg gummy starts about 33 times higher than your own night's peak, and can still be there at the alarm.
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In a 2023 test of 25 US melatonin gummies, most held 1.2 to 1.7 times their label, and one held none.
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Ordinary room light before bed made melatonin start later in 99 percent of 116 young adults.
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A double espresso 3 hours before bed pushed people's melatonin rhythm about 40 minutes later.
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For jet lag across 5 or more time zones, 0.5 to 5 mg at bedtime in the new time zone for the first 4 nights, and daylight at the right hours.
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After a night shift, dark glasses home and a dark room come first. Melatonin added about 24 minutes of day sleep in trials.
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To match a normal night's peak with tart cherries, you'd have to eat about 49 pounds of them.
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Under 18, pregnant or breastfeeding, or on a daily prescription? Ask a doctor before taking any melatonin.
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Two weeks of nights on and off melatonin tell you more about your own sleep than any average.
The studies
When to take it
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2005. The time young adults woke on days with no alarm was the best guide to when their own melatonin started.
Burgess and Eastman, Journal of Sleep Research
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2010. 0.5 mg moved the body clock as far as 3 mg when each was taken at its best hour, 2 to 4 hours before people's own melatonin started.
Burgess and others, 34 adults in a lab
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2024. The earlier people took it before bed, the more it helped them fall asleep, and the effect grew up to about 4 mg.
Cruz-Sanabria and others, 26 trials
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2018. 0.5 mg an hour before the bedtime they wanted, for 4 weeks, got them to sleep 34 minutes earlier than a placebo.
Sletten and others, 116 people with late body clocks
How much, and how long it lasts
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2013. Melatonin got people to sleep about 7 minutes faster on average, 5.5 when machines measured it.
Ferracioli-Oda and others, 19 trials, 1,683 people
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1994. 0.1 to 0.3 mg raised blood melatonin to a normal night's level, and every daytime dose made people sleepier.
Dollins and others, 20 men
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2001. 0.3 mg restored sleep in poor sleepers, and 3 mg stayed in the blood into daylight.
Zhdanova and others, 30 adults over 50
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2016. A tablet peaked about 40 minutes after it was swallowed, then halved about every 54 minutes.
Andersen and others, 12 men
Light, coffee, drinks and your own melatonin
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1980. A bright enough light switched off people's melatonin at night, which ordinary room light had seemed not to do.
Lewy and others, 6 people
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2011. Room light before bed made melatonin start later in 99 percent of them and cut its night short by about 90 minutes.
Gooley and others, 116 adults aged 18 to 30
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2003. Light before the low point of the night moved the body clock later, and light after it moved the clock earlier.
Khalsa and others, 21 adults
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2015. Reading on a light-emitting e-reader before bed meant less melatonin, a later clock and a slower start to sleep than a printed book.
Chang and others, a sleep lab study
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2016. After a day with plenty of bright light, 2 hours of tablet reading made no difference to sleep or melatonin.
Rångtell and others, 14 people
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2015. The caffeine in a double espresso 3 hours before bed pushed the melatonin rhythm about 40 minutes later.
Burke and others, Science Translational Medicine
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2007. Vodka finished an hour before bed cut their own melatonin by 15 to 19 percent over the next few hours.
Rupp and others, 29 young adults
Age and food
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1988. Nighttime melatonin peaked at ages 1 to 3, was much lower by the late teens, and drifted lower into old age.
Waldhauser and others, 367 people aged 3 days to 90
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1999. Healthy adults aged 65 to 81 on no medicines made as much melatonin as young men.
Zeitzer and others, 34 healthy older adults
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2017. Eggs and fish held the most melatonin among animal foods, and nuts the most among plants.
Meng and others, a review
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2001. Montmorency tart cherries held 13.46 nanograms of melatonin per gram, so a cup holds about 0.002 mg.
Burkhardt and others, tart cherries
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2012. A week of tart cherry concentrate raised urine melatonin and improved sleep on wrist monitors.
Howatson and others, 20 adults
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2024. Two weeks of 500 mg tart cherry capsules changed no sleep measure.
Tucker and others, 34 adults
What's in the bottle
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2023. 22 missed their label, holding 74 to 347 percent of it, and one held no melatonin.
Cohen and others, 25 US gummies
Trips and night shifts
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2002. Melatonin at bedtime in the new time zone cut jet lag after 5 or more time zones, and doses above 5 mg did no better.
Herxheimer and Petrie, Cochrane, 10 trials
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2009. In real travelers, the body clock moved about 57 minutes a day after flying east and 92 after flying west.
Eastman and Burgess, a review
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2014. Melatonin added about 24 minutes of day sleep after night shifts, on low-quality evidence.
Liira and others, Cochrane, shift workers
Safety
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2019. Side effects were mild and uncommon, mostly daytime sleepiness, headache and dizziness, in trials of a month or less.
Besag and others, 37 trials
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2025. A year or more of melatonin in health records went with more heart failure, in a design that couldn't show cause.
A conference abstract, American Heart Association (not peer reviewed)
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2026. Recent melatonin use wasn't linked to heart disease or heart failure.
Khan and Lima, US national survey data
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2000. The antidepressant fluvoxamine made melatonin levels about 17 times higher.
Härtter and others, 5 men
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2022. Reports to US poison centers about children and melatonin rose 530 percent from 2012 to 2021.
Lelak and others, CDC MMWR
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2015. Melatonin eased nerves before surgery more than a placebo did.
Hansen and others, Cochrane, 12 trials
Resources
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Melatonin: What You Need To Know The US government's plain summary, updated May 2024.
National Center for Complementary and Integrative Health
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Questions and Answers on Dietary Supplements Why nobody checks a supplement before it's sold.
US Food and Drug Administration
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Melatonin and children's sleep What pediatricians tell parents, updated January 2026.
American Academy of Pediatrics, HealthyChildren.org
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How Much Sleep Do I Need? Sleep and the late teen body clock, written for teens.
Nemours TeensHealth
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Sleep How much sleep teens need, and how many get it.
CDC, Youth Risk Behavior Surveillance System
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Poison Help, 1-800-222-1222 Call if a child swallowed melatonin, and 911 if they can't be woken or have trouble breathing.
US poison centers
