Calculator
Melatonin Timing Calculator
Melatonin is a timing signal, not a sedative. To shift your sleep earlier, take a small dose (0.3–0.5 mg) ~5 hours before target sleep, not at bedtime. Taking 5 mg at lights-out — what most people do — misses both the timing and the dose.
Take the chronotype quiz if unsure.
Take melatonin at
4:00pm
Dose: 0.3–0.5 mg. Higher doses do not work better — they often work worse.
Taking melatonin ~5 hours before your endogenous melatonin onset (DLMO) produces the largest phase-advance effect — pulling your sleep window earlier over a few days.
Reminder: Melatonin is a timing signal, not a sedative. Most users mistakenly take 3–10 mg right before bed expecting a sleeping pill effect, miss the timing entirely, and conclude it doesn't work. Use it for jet lag, delayed sleep phase, and circadian shifting — not as a knockout.
How it works
Your body produces its own melatonin, with onset typically ~2 hours before habitual sleep — a marker called DLMO (dim light melatonin onset). For phase-advancing effect (pulling sleep earlier), exogenous melatonin works best taken roughly 4–5 hours before DLMO, which is about 6–7 hours before habitual sleep onset (Burgess et al, 2008).
For a separate, weaker effect — mild sedation — take 0.3–1 mg about 30 minutes before bed. This is what most users do, but the effect size is much smaller than people expect.
Dose matters less than people think. Studies comparing 0.3 mg, 1 mg, 3 mg and 5 mg consistently find that lower doses (0.3–1 mg) work as well or better than higher doses for phase shifting. Higher doses saturate receptors and produce longer half-lives that can leave residual grogginess.
Why it matters
Melatonin is the most over-the-counter sleep supplement on earth and the most consistently misused. If you've taken 5 mg at bedtime and concluded melatonin doesn't work, you've tested the wrong protocol. The right protocol works.
Sources
- 1Burgess, H. J. et al.. A three pulse phase response curve to three milligrams of melatonin in humans · Journal of Physiology · 2008PMID 18077413