When to take it

How long does it take for melatonin to work?

By GyroscopeUpdated November 14, 20265 sources

A regular tablet reaches its peak in your blood about 40 minutes after you swallow it. That’s why we say to take it 1 to 3 hours before bed. By the time you turn the lights off, the dose has peaked and your body has had time to get the message that it’s evening.

People ask this standing at the bathroom sink with the tablet in their hand, and the label says “before bed”. Swallowed at lights out, it’s still climbing toward its peak while you lie there wondering why you’re awake.

We’d take it early and dim the lights after. If your goal is moving your whole sleep schedule earlier, give it several days, because that job runs on a slower clock.

It’s like putting a kettle on. The water was always going to boil, but if you switch it on when you want the tea, you’ll be standing there waiting.

What happens in the first hour

In a 2016 study in Copenhagen, 12 healthy men took 10 mg by mouth on one day and 10 mg into a vein on another. By mouth, their blood levels peaked at 40.8 minutes on average. Only about 3 percent of the swallowed melatonin made it into their blood, and the same tablet peaked more than 3 times higher in some men than in others, so one pill can hit two people quite differently.

The sleepiness itself comes on fast. In 1994, researchers at MIT gave 20 men doses from 0.1 to 10 mg at 11:45am and tested them at 1:30pm. Every dose made them fall asleep faster on a simple lab sleep test and feel sleepier, and every dose made them slower on a listening task.

When “working” means moving your clock

If you’re using melatonin to move your bedtime earlier, the first night tells you very little. In the 2010 Chicago lab study, people took 0.5 mg once a day for 3 days in dim light, and the best-timed doses moved their body clocks up to about 1.5 hours earlier, as much as 2.9 hours in some people. Out in real life it’s slower. In a 4-week trial of 116 people with late body clocks, 0.5 mg an hour before a fixed bedtime brought sleep 34 minutes earlier than a placebo with the same bedtime.

Slow-release and gummies

Slow-release tablets are built to spread the dose over the night, so they rise more slowly and last longer. In a 1995 trial in older adults with insomnia, 2 mg slow-release helped them stay asleep and the same dose as a regular tablet helped them fall asleep. Follow the label for when to take a slow-release one. Gummies often hold more than the label says, which the gummies answer covers.

Try your own dose and time in the tool below to see when it peaks and when it’s gone. Don’t drive after a dose.