Mode 1 — Dose range finder
Select your age group and your goal. The result shows the commonly cited dose range and timing — plus the "start low" rule.
Mode 2 — Timing guide
Enter the time you want to be asleep. The tool computes the suggested intake window.
Mode 3 — Safety check
Tick anything that applies to you. The checker flags the main published cautions and interactions.
Quick facts (from published guidance)
| Topic | What sources say |
|---|---|
| Typical adult starting dose | Start low: 0.5 mg to 1 mg, taken 30 minutes before bedtime. |
| Commonly cited adult range | 0.5 mg to 5 mg per night. More is not better. |
| Doses above which benefit rarely increases | Above 5–10 mg rarely improves sleep and may increase side effects such as morning grogginess, vivid dreams, or headaches. |
| Usual timing | 30 to 60 minutes before the desired bedtime. |
| Circadian / phase-delay timing | 0.5 mg, 2 to 3 hours before the desired bedtime (sleep-specialist protocol). |
| Jet lag | Take it at the local bedtime of your destination, 30 to 60 minutes before sleep. |
| Children and teenagers | No standard over-the-counter dose — talk to a doctor or pharmacist first. |
| Pregnancy / breastfeeding | Not known to be safe — avoid without medical advice. |
| Supplement quality | Actual melatonin content can vary; experts recommend independently tested products (USP, NSF, or ConsumerLab). |
Frequently asked questions
How much melatonin should an adult take?
Commonly published guidance describes a starting dose of 0.5 mg to 1 mg, taken about 30 minutes before bedtime. The commonly cited adult range is 0.5 mg to 5 mg per night. The goal is the lowest dose that helps you fall asleep — more melatonin is not better, and higher doses can cause morning grogginess, vivid dreams, or headaches. If sleep problems continue, talk to a health care provider instead of raising the dose on your own.
Is a higher dose of melatonin more effective?
No. Sources describe doses above 5–10 mg as rarely more effective, and sleep specialists note that higher doses can be counterproductive — they may leave you sleepy during the day and raise the chance of side effects. If 1 mg is not helping, do not jump straight to high doses; ask a doctor or pharmacist.
When should I take melatonin?
Usually 30 to 60 minutes before your desired bedtime. For circadian purposes (shifting sleep earlier), sleep specialists describe 0.5 mg taken 2 to 3 hours before the desired bedtime. Do not drive or operate machinery for several hours after taking melatonin.
How should I take melatonin for jet lag?
Take it at the local bedtime of your destination, 30 to 60 minutes before you plan to sleep. The exact schedule depends on how many time zones you cross and in which direction — ask a health care provider for a plan rather than guessing.
Can children or teenagers take melatonin?
There is no standard over-the-counter dose for anyone under 18. The NCCIH notes uncertainties about the right dose, timing, long-term effects, and possible effects on hormonal development (including puberty), because melatonin is a hormone. Work with a health care provider before giving melatonin to a child or teenager.
What are the common side effects of melatonin?
The most commonly reported effects are daytime sleepiness or drowsiness, dizziness, headache, vivid dreams or nightmares, nausea, fatigue, and a cold feeling. Older adults may be more sensitive, especially with higher doses.
What drugs interact with melatonin?
Melatonin may interact with blood thinners (such as warfarin), medicines for diabetes or blood pressure, sedatives and prescription sleep medicines, immunosuppressants (such as after an organ transplant), anticonvulsants, and birth control pills. Research on drug interactions with melatonin is incomplete — always tell your health care provider about all medicines and supplements you take.
Can I take melatonin while pregnant or breastfeeding?
It is not known if melatonin is safe during pregnancy or breastfeeding. Do not use it without medical advice. Talk to your doctor or pharmacist about alternatives for sleep problems during this time.
Is this calculator medical advice?
No. It is an educational restatement of commonly published guidance (adult starting dose 0.5 mg–1 mg, common range 0.5 mg–5 mg, timing 30–60 minutes before bed; under-18s, pregnancy, and breastfeeding: ask a provider). It does not know your health history, medicines, or conditions, and it does not prescribe a dose for any individual. Always follow the label on your package and check with a doctor or pharmacist when unsure.