Timing is a big part of how melatonin is used. This calculator shows where government health sources place the dose relative to your bedtime, for each common form.

Enter the time you want to be asleep and pick the form you take.

Where each window comes from

For slow-release tablets, the NHS says the usual dose for short-term sleep problems in adults is one 2 mg tablet taken 1 to 2 hours before bedtime, with food.

For standard tablets, the NIH describes a trial in people with delayed sleep-wake phase disorder where melatonin taken 1 hour before the desired bedtime helped them fall asleep about 34 minutes earlier. The NHS suggests taking standard tablets 2 hours before or after food.

Neither source gives separate timing for sublingual or dissolvable forms, so the tool sends you to the product label for those.

What melatonin can and cannot do

The NIH says melatonin may help with jet lag and delayed sleep-wake phase disorder. For chronic insomnia, guidelines do not recommend it because the evidence is not strong enough, and they put cognitive behavioral therapy first.

For shift workers, studies were small or inconclusive. This calculator gives general timing for ordinary evenings and does not cover jet lag or shift work, which use different schedules.

Doses and product quality

There is no dose advice here. The NHS describes prescription amounts, and a pharmacist or doctor should guide anything beyond the label.

The NIH also warns that some melatonin products do not contain what the label says. A study of 31 supplements found most did not match their labels, and some gummies held far more than listed.

Safety points worth knowing

Short-term use appears safe for most people, but long-term safety is unknown. People with epilepsy or on blood thinners need medical supervision, and there is little research in pregnancy and breastfeeding. Older adults may feel drowsy the next day.

For children, speak with a health care provider first, and keep melatonin out of reach, since accidental ingestion is a common reason for emergency visits.

Around the rest of your evening

Caffeine late in the day can work against sleep, and the Caffeine Intake and Cutoff Time calculator estimates when to stop. The Magnesium Dosage Calculator and the Supplement Stack Builder cover other things people commonly discuss for sleep.

Where this comes from

Evidence and safety points come from the NIH National Center for Complementary and Integrative Health fact sheet on melatonin.

Timing for slow-release tablets comes from the UK NHS guide to how and when to take melatonin.

This calculator is for general education only and is not medical or professional advice. Speak with a qualified professional about ongoing sleep problems, or before giving melatonin to a child.