For most adults, taking one to five 1mg melatonin tablets (1 to 5mg total) is the typical recommended range, with 5mg generally considered the maximum daily dose. Starting with just one 1mg tablet is the best approach, since lower doses are often just as effective as higher ones and produce fewer side effects.
How Many 1mg Tablets to Start With
Start with a single 1mg tablet. That’s enough for many people to notice a difference in how quickly they fall asleep. If one tablet doesn’t help after a few nights, you can add another, working your way up gradually. The Mayo Clinic identifies 5mg or fewer as the typically recommended maximum, so five 1mg tablets would be the upper end of standard use. The NHS lists 10mg as the maximum prescribed dose for longer-term insomnia, but that’s under medical supervision and not a target to aim for on your own.
More melatonin doesn’t necessarily mean better sleep. Your body produces less than 0.1mg of melatonin naturally each night, so even a single 1mg tablet is already many times higher than what your brain releases on its own. Some sleep specialists find that doses in the 0.5 to 1mg range work just as well as larger doses for helping people fall asleep, with fewer issues like morning grogginess.
What Happens if You Take Too Much
Melatonin isn’t dangerous in the way that many sleep medications can be. Taking more than you need won’t cause a life-threatening overdose, but it can make you feel worse rather than better. Common symptoms of taking too much include headache, dizziness, nausea, and excessive daytime drowsiness the next morning. Some people also experience vivid dreams or feel “foggy” well into the following day.
Melatonin stays active in your body for about five hours, with a half-life of 40 to 60 minutes. That means if you take a large dose, the effects can linger longer than a normal night’s sleep requires, which is why morning grogginess is the most frequent complaint from people who overdo it.
Your Tablets May Not Contain What the Label Says
One important wrinkle with 1mg melatonin tablets: the actual amount of melatonin inside may not match the label. A study published by researchers and reported by the American Academy of Sleep Medicine analyzed 31 melatonin supplements and found that more than 71% were off by more than 10% from the labeled dose. The actual melatonin content ranged from 83% less to 478% more than what the bottle claimed. Even different batches of the same product varied by as much as 465%.
This means your “1mg” tablet could contain anywhere from a tiny fraction of a milligram to nearly 5mg. It’s one more reason to start low and pay attention to how you feel rather than assuming the number on the label is precise.
When and How to Take It
Take your melatonin 30 to 60 minutes before you want to fall asleep. It works by signaling to your brain that it’s time to wind down, mimicking the natural melatonin your pineal gland releases when darkness falls. Taking it too early or too late reduces its usefulness.
Melatonin works best as a nudge to your sleep-wake cycle, not a sedative. Pairing it with good sleep habits (a dark room, consistent bedtime, limited screen time before bed) makes a bigger difference than increasing the dose. If you’re using it for jet lag, doses in the 3 to 6mg range are more common, taken at the bedtime of your destination time zone.
Medications That Interact With Melatonin
Melatonin interacts with more medications than most people realize. If you take blood thinners, melatonin can increase your risk of bleeding. It can worsen blood pressure in people on blood pressure medications and affect blood sugar levels in people taking diabetes drugs. Combined with any sedative, including alcohol, it can amplify drowsiness beyond what either substance would cause alone.
Hormonal birth control can also intensify melatonin’s sedative effects. And one antidepressant used for OCD, fluvoxamine, dramatically increases melatonin levels in the blood, potentially causing excessive drowsiness. If you take seizure medications, melatonin may reduce their effectiveness. Anyone on immunosuppressants should also use caution.
Melatonin for Children
Children need much lower doses. Most children who benefit from melatonin do well on 3 to 6mg, but starting with the lowest available dose is important. Long-term safety data in children is limited, and there are open questions about whether ongoing use could affect growth and development during puberty. Side effects in kids include morning sleepiness, headache, and increased bedwetting.
An additional concern for children is that some melatonin supplements have been found to contain undisclosed ingredients like serotonin or CBD, or drastically different amounts of melatonin than labeled. Because melatonin is sold as a dietary supplement in the United States rather than a regulated medication, quality control varies widely between brands.
Long-Term Use
Unlike many prescription sleep aids, melatonin does not appear to cause dependency. You’re unlikely to need increasingly higher doses over time to get the same effect, and stopping it doesn’t typically cause rebound insomnia. That said, long-term safety data beyond a few months is still limited, so using the lowest effective dose for the shortest time that helps is a reasonable approach. If one or two 1mg tablets are doing the job, there’s no reason to take more.