Most adults should start with 0.5 to 2 mg of melatonin, taken 30 minutes to 2 hours before bedtime. That’s far less than the 5 or 10 mg tablets you’ll find lining store shelves, but lower doses are consistently effective and less likely to cause side effects. The right amount depends on why you’re taking it, your age, and whether you’re using an immediate-release or slow-release formula.
Starting Dose for Adults
For short-term sleep problems, 2 mg of a slow-release tablet taken 1 to 2 hours before bed is a standard starting point. If your sleep issues persist, the dose can gradually increase, but the ceiling is 10 mg per day. Most people never need to go that high.
The key principle is to start low. Your body naturally produces melatonin in tiny amounts to signal that it’s time to sleep. A supplement is meant to nudge that signal, not overwhelm it. Taking more doesn’t necessarily make you sleepier. In fact, higher doses can leave you groggy and foggy the next morning, which defeats the purpose.
Timing Matters as Much as Dose
Melatonin isn’t a sedative that knocks you out on contact. It works by shifting your body’s internal clock, so when you take it is just as important as how much. For general sleep difficulties, 30 minutes to 2 hours before your intended bedtime is the sweet spot. Taking it too early can make you drowsy before you’re ready for bed. Taking it too late means it hasn’t kicked in when your head hits the pillow.
Immediate-release melatonin clears your system relatively quickly, with blood levels dropping back to baseline within about 5 hours. Slow-release formulations stay active for roughly 7 hours, more closely mimicking the natural melatonin curve your brain produces overnight. If you fall asleep easily but wake up at 3 a.m., slow-release is the better choice. If you just struggle to fall asleep initially, immediate-release works fine.
Doses for Jet Lag
Jet lag calls for a different approach. The CDC notes that 0.5 to 1 mg is often enough to shift your circadian rhythm, and doses above 5 mg are not recommended because excess melatonin lingers in your system and can end up active at the wrong time of day, making jet lag worse rather than better.
The direction you’re traveling changes the strategy. For eastward travel (where you need to fall asleep earlier than your body expects), take melatonin before bedtime at your destination. For westward travel (where you need to stay up later), taking melatonin in the morning by your body’s internal clock can help delay your sleep phase. Avoid taking it during the hours your body is already producing its own melatonin, roughly midnight to 5 a.m. by your home time zone, because supplementing during that window doesn’t add much benefit.
Melatonin Doses for Children
There are no formal dosage guidelines for children, which makes this trickier. The American Academy of Pediatrics recommends starting at the lowest available dose, typically 0.5 to 1 mg, given 30 to 90 minutes before bedtime. Most children who benefit from melatonin, including those with ADHD, don’t need more than 3 to 6 mg.
Safety data on long-term use in kids is limited. Short-term use appears relatively safe, but there are open questions about how supplemental melatonin might affect growth and development, particularly during puberty. The most common side effects in children are morning drowsiness and increased nighttime urination.
One serious concern: between 2012 and 2021, there were more than 260,000 reports of children accidentally ingesting melatonin. Gummy formulations look and taste like candy, so storing them out of reach is essential. Adding to the risk, studies have found that some melatonin products contain far more of the hormone than the label claims, and some contain unlisted ingredients like CBD.
Doses for Older Adults
Clinical trials in adults aged 55 and older have consistently used 2 mg of slow-release melatonin nightly, and this dose has shown modest benefits for sleep quality. Older adults produce less natural melatonin than younger people, which is one reason sleep patterns tend to shift with age. But that reduced production also means a lower dose can be effective. Starting at 2 mg and adjusting from there is a reasonable approach.
Why More Isn’t Better
Melatonin supplements in the U.S. are sold as dietary supplements, not regulated medications. This means you can buy 10 mg gummies without a prescription, but that doesn’t mean 10 mg is an appropriate dose. The most common side effects at any dose include headache, dizziness, nausea, and daytime drowsiness. At higher doses, people also report vivid dreams or nightmares, mood swings, irritability, stomach cramps, and reduced alertness.
Drowsiness can persist for hours. You should avoid driving or operating machinery within five hours of taking melatonin, which is worth remembering if you take it and then can’t sleep.
Melatonin also interacts with several categories of medication, including blood thinners, seizure medications, birth control, blood pressure drugs, diabetes medications, and immunosuppressants. If you take any of these, the interaction is worth checking before you add melatonin to your routine.
Label Accuracy Is a Real Problem
Because melatonin is classified as a supplement in the United States, manufacturers don’t face the same quality controls as pharmaceutical companies. Independent testing has found that the actual melatonin content in supplements can differ dramatically from what’s printed on the label. Some products contain several times the listed amount. This makes starting with a low dose even more important: if the label says 1 mg but the tablet contains 3 mg, you’re already taking more than you intended. Choosing products from brands that undergo third-party testing can reduce this risk.