Myth or fact

Should you take melatonin right at bedtime?

Short answerNo

By GyroscopeUpdated November 14, 20268 sources

No. In a 2024 analysis of 26 trials, the more time people left between the dose and sleep, the more it helped, and the authors suggested about 3 hours before bed. To move your body clock earlier, the best time is even earlier, about 5 hours before your usual bedtime. Lights out is about the least useful time to take it at home.

Why it seems obvious

The bottle says to take it before bed, and for a sleeping pill that’s how it works. Doctors have done the same. The 2024 review named the schedule most used in clinics: 2 mg, 30 minutes before the bedtime you want. Most advice online still says 30 to 60 minutes.

Preheating the oven

Taking melatonin at lights out is like turning the oven on when the food goes in. It’ll get there, but dinner’s late.

Melatonin’s job is to tell your body night is coming, and your body needs that message ahead of time. A tablet also needs about 40 minutes just to reach its peak in your blood.

What the studies found

The 2024 analysis. Researchers pooled 26 double-blind trials, from 1987 to 2020, with 1,689 observations. The time between taking it and going to sleep predicted how much it shortened the time to fall asleep. The authors suggested moving the dose to about 3 hours before the bedtime you want.

An early MIT study. Volunteers took 0.3 or 1 mg at 6, 8 or 9pm. Every dose at every time shortened the time to fall asleep in the lab, with no grogginess the next morning. Most volunteers could tell melatonin from a placebo when they took it at 6 or 8pm.

The 2010 clock study. For moving the body clock earlier, 0.5 mg worked best 2 to 4 hours before a person’s own melatonin started, which is the afternoon or early evening for most people. Eastman and Burgess put the best time for 0.5 mg at about 4.5 hours before sleep.

When your own melatonin starts. In young adults on their own schedules it starts about 2.5 hours before bedtime. At lights out it’s already been rising for a couple of hours, so a tablet mostly repeats a message your brain has already sent.

The best case for bedtime

“It makes me drowsy, so I want it at bedtime.” Even then, an hour or more ahead beats lights out, since the peak comes about 40 minutes after you swallow it.

There are two real cases where around bedtime is right. The first is jet lag. In the Cochrane review, 9 of 10 trials found melatonin taken close to bedtime at the destination, 10pm to midnight, reduced jet lag after 5 or more time zones. Your body is still on home time, so 10:30pm in Paris is 4:30pm on a New York body clock, which is right in the window that moves a clock earlier.

The second is people whose clocks run very late. In a 2018 Australian trial, people with delayed sleep phase took 0.5 mg an hour before the bedtime they wanted, and their sleep came 34 minutes earlier than on placebo. But they were chosen because their own melatonin started after that bedtime, or within 30 minutes before it, so an hour before bed was still early on their body clock.

When to take it instead

To move your bedtime earlier, the melatonin window counts back from the time you wake on a day with no alarm. Wake at 8am on free days and that’s 0.5 mg between 5:35 and 7:35pm.

Take it somewhere you can dim the lights, and don’t drive after a dose.