A reasonable starting dose of melatonin for most healthy adults is 1 milligram (mg), taken about 1 to 2 hours before bedtime. If needed, a typical adult range is 1 to 3 mg. Higher doses do not necessarily improve sleep and may cause next-day drowsiness, headache, dizziness, or nausea.

Situation Common adult approach Timing
Occasional trouble falling asleep Start with 1 mg; a typical range is 1 to 3 mg About 1 to 2 hours before bed
Jet lag Dosing varies. One common medical regimen is 3 mg once daily for up to 5 days At bedtime in the destination time zone
Delayed sleep schedule Some adults use 0.5 to 1 mg Often several hours before bedtime, with guidance from a clinician
Chronic insomnia Do not keep increasing the dose without medical advice Cognitive behavioral therapy for insomnia, or CBT-I, is generally preferred

The right dose depends on why you are taking melatonin, the product's formulation, your other medicines, and your health history. There is no universally accepted maximum dose for every adult sleep problem.

How to Take Melatonin Safely

  1. Start with 1 mg instead of taking a 5 mg or 10 mg tablet.
  2. Take it at the same time on the nights you use it.
  3. Do not take an extra dose in the middle of the night if it does not work.
  4. Use the lowest dose that helps.
  5. If melatonin has not helped after about one to two weeks, stop self-treating and discuss the sleep problem with a healthcare professional.

Melatonin mainly signals that it is time for the body to prepare for sleep. It is not a strong sedative, so taking more may not help you fall asleep faster. Keeping lights low and avoiding bright screens before bed may also support the body's natural melatonin signal.

When Adults Should Ask a Clinician Before Taking Melatonin

Speak with a healthcare professional before using melatonin if you:

  • Are pregnant or breastfeeding
  • Take blood thinners, seizure medication, or other prescription medicines
  • Have epilepsy, an autoimmune condition, diabetes, or high blood pressure
  • Have dementia, or are an older adult who is prone to daytime drowsiness
  • Have persistent insomnia, loud snoring, gasping during sleep, or marked daytime sleepiness

NCCIH says short-term melatonin use appears relatively safe for most people, but the long-term safety of supplements remains unclear. Melatonin can cause headache, dizziness, nausea, and sleepiness.

Is Melatonin Appropriate for Chronic Insomnia?

Melatonin is not usually the first-line treatment for ongoing insomnia. The American Academy of Sleep Medicine and the American College of Physicians found insufficient evidence to recommend melatonin supplements for chronic insomnia, while CBT-I is strongly recommended as an initial treatment.