Melatonin daily dose: how much to take and when

The short answer: 0.3–3 mg, 30–60 minutes before desired bedtime — less is usually more

Melatonin is an endogenous hormone the pineal gland secretes in response to darkness. Supplemental melatonin is widely used for sleep-onset insomnia and jet lag. The most common mistake is taking too much — physiologic night-time plasma melatonin levels are reached with just 0.3 mg, and larger doses (5–10 mg) do not work better for most people, while raising the chance of side effects.

Evidence-based doses

• Sleep-onset insomnia (adults): 0.3–3 mg, 30–60 minutes before bedtime. Start with the lowest dose.
• Jet lag: 0.5–3 mg at local bedtime for 3–5 nights after arrival (westbound) or before departure (eastbound).
• Delayed sleep-wake phase disorder: 0.5 mg, 4–6 hours before sleep (advancing phase).
• Shift work sleep disorder: 1–5 mg before daytime sleep.
• Children with ASD/ADHD-related sleep problems: 0.5–3 mg, under pediatrician direction.

What melatonin does and does not do

• Helps you fall asleep faster when biological clock is shifted (jet lag, delayed sleep phase)
• Does not reliably help you stay asleep — not a sedative-hypnotic
• Timing matters more than dose — melatonin is a chronobiotic (signals "it's night"), not a sleeping pill
• Not for chronic maintenance insomnia — see a doctor if insomnia persists >3 weeks

Safety and side effects

• Short-term safety (weeks to months): generally good. Mild headache, daytime drowsiness, vivid dreams, nausea.
• (years): less studied, but no consistent harmful signals.