Melatonin is not a sedative — it is a timing signal. Most people take it at the wrong dose, at the wrong time, for the wrong purpose. Used correctly, it is one of the most well-evidenced interventions for circadian misalignment.
Key Takeaways
- 10mg melatonin produces serum levels 50–100x above your natural nocturnal peak — can suppress your own production over time
- Melatonin taken at the wrong time can phase-delay your clock — making your sleep problem worse, not better
- Best-supported uses: jet lag (strong Cochrane Review evidence), shift work, and delayed sleep phase advancement
- For phase-advancing: take 0.3–0.5mg 4–6 hours before your TARGET bedtime, not your current bedtime
- Not the right tool for insomnia driven by anxiety, sleep maintenance problems, or poor quality in correctly-timed sleepers
Correct Protocol by Use Case
- Phase advancement (shift clock earlier): 0.3–0.5mg taken 4–6 hours before desired bedtime. If target is 11pm, take at 5–7pm.
- Sleep onset assistance (aligned sleeper): 0.5–1mg taken 30–60 min before target bedtime. Do not exceed 1mg for this use.
- Jet lag — eastward travel: 0.5mg at 10–11pm local destination time for 3–4 nights after arrival.
- Jet lag — westward travel: Melatonin less necessary; morning light at destination is usually sufficient.
- Find minimum effective dose: Start at 0.3mg. Increase to 0.5mg only if no response after 3–5 nights. Avoid exceeding 1mg for non-clinical use.
What to Watch in Your Data
Sleep onset latency
Clearest signal. If correctly timed for your use case, onset latency decreases within 3–5 consistent nights.
Sleep timing trend
For phase advancement: sleep window drifting earlier over 1–2 weeks = working. Watch for consistent earlier onset in the data.
Morning grogginess
Groggy despite adequate sleep = dose too high or timing too late. Drop to 0.3mg and/or take 30 min earlier.
REM proportion
Better-aligned onset should improve REM timing over 2–3 weeks. No REM improvement = misalignment is not the primary issue.