🌙 Melatonin Dosage Guide

Melatonin works best at small doses taken at the right time: start 0.5 to 1 mg, with most evidence supporting 1 to 5 mg, taken 1 to 2 hours before the target bedtime. It is a darkness signal for the brain's clock, not a sedative, which is why timing matters more than milligrams and why 10 mg is not "stronger sleep" but usually just more side effects.

Pick your use case and target bedtime. The guide returns a starting dose, the studied range, and the right timing. Melatonin helps sleep onset, jet lag, and shifted schedules; it does little for staying asleep, which is a different problem.

How to Use This Calculator

Choose whether you need help falling asleep, beating jet lag, or sleeping after shift work, and enter your target bedtime. Start at 0.5 to 1 mg taken 1 to 2 hours before bed. Give it several nights before judging. If 1 mg does nothing after a week, a cautious step to 3 mg is reasonable; beyond 5 mg, talk to your doctor rather than escalating.

Why Low and Early Beats High and Late

Endogenous melatonin rises in the evening as darkness falls; a small supplement taken 1 to 2 hours before bed advances and reinforces that rise. Dose-response studies show 0.5 to 1 mg shifts circadian timing effectively, and higher doses do not proportionally improve sleep: they mostly extend how long melatonin stays high, causing morning grogginess and vivid dreams. The hormone's half-life is short (under an hour for immediate release), so taking it at bedtime misses the window when the clock is most responsive. Extended-release formulations exist for sleep maintenance but have thinner evidence.

Worked Example

Target bedtime 11:00 PM for sleep onset: Start 0.5-1 mg, taken Take around 9:30 PM (1-2h before bed). The guidance reads "Start 0.5-1 mg; typical range up to 5 mg". Most people buy 5 or 10 mg tablets and take far more than studied doses: cutting a 1 mg tablet in half is closer to the evidence than a whole 10 mg.

Matching Dose to Problem

Trouble falling asleep: 0.5 to 3 mg timed 1 to 2 hours before bed, the best-supported use. Jet lag eastward: 0.5 to 3 mg at local bedtime for a few nights plus morning light. Shift work: 1 to 3 mg before daytime sleep in a dark room. Waking at 3 AM and cannot return to sleep: melatonin is the wrong tool; that pattern points to stress, sleep apnea, or other causes worth evaluating. Children, pregnancy, and autoimmune conditions need a doctor's input before any use.

Supplements Are Unregulated Doses

Independent testing has found melatonin products often contain far more or less than the label, sometimes with unlisted serotonin precursors. Buy USP-verified brands when possible. Melatonin can interact with blood thinners, immunosuppressants, diabetes drugs, and blood pressure medicines. Do not drive if groggy. This tool is for informational purposes only, not medical advice. Dosing decisions must be confirmed with your doctor or pharmacist. Consult a healthcare professional.

Related tools: sleep cycle calculator and medicine 3-times-a-day scheduler.

For informational purposes only, not medical advice. Dosing decisions must be confirmed with your doctor or pharmacist. Consult a healthcare professional.