Is 3 mg of melatonin too much?
Not too much, but often more than you need. In a trial of adults over 50, 3 mg improved sleep but kept melatonin in their blood into the daylight hours, while 0.3 mg also worked. Taken at 10:30pm, 3 mg stays above your own night’s peak until somewhere between 2:10 and 4:10am.
3 mg sounds small next to the 5 and 10 mg bottles beside it, so it’s where a lot of careful people start. It’s about 10 times the peak your own brain makes on a normal night.
We’d try 1 mg first, 1 to 3 hours before bed. If 3 mg already works for you and you wake up clear-headed, there’s no reason to change it. If mornings feel foggy, drop the dose before you change the hour.
It’s like using a garden hose to water a houseplant. The plant gets watered, and some of it ends up on the floor.
What the trials found at 3 mg
In 2001, researchers at MIT gave 30 adults over 50 a placebo, 0.1, 0.3 and 3 mg, each for a week, 30 minutes before bed. 0.3 mg restored sleep in the poor sleepers and brought their night melatonin back to normal. 3 mg also improved sleep, but it lowered their body temperature and their melatonin was still raised into daylight.
For moving your body clock earlier, 3 mg and 0.5 mg did about the same job. In the 2010 Chicago lab study, each moved the clock by a similar amount when taken at its own best time, and the best time for the bigger dose was earlier. The same lab’s working estimate puts 3 mg about 5 hours before your own melatonin starts, against about 2 hours for 0.5 mg.
A 3 mg night, by the numbers
| 3 mg at 10:30pm | |
|---|---|
| Peak | About 10 times a normal night’s peak, at about 11:10pm |
| Back under your own night’s peak | 2:10 to 4:10am |
| Left at 7am, fast to slow clearing | Well under your own level |
| As a gummy, most likely real dose | 3.6 to 5.1 mg |
| Tart cherries holding the same melatonin | About 491 pounds |
The timing comes from a measured half-life of about 54 minutes in a 2016 Copenhagen study, with 1.5 hours as the slow end for people who clear it slowly. The gummy row comes from a 2023 test of 25 US products, where most held 1.2 to 1.7 times the label. The cherries come from a measured 13.46 nanograms per gram in Montmorency tart cherries.
If you’re over 60, the slow end is the one to plan around. Older adults in that 2001 trial still had raised melatonin in daylight, and the older adults answer suggests starting at 0.3 to 0.5 mg.
Put 3 mg and your alarm into the tool below to see your own night. Don’t drive after a dose.
6 sources
- 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
- Eastman CI, Burgess HJ, How to travel the world without jet lag, Sleep Medicine Clinics, 2009pubmed.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
