Research
Hormonal
Incorrect timing or high doses of melatonin administered late relative to endogenous melatonin onset can result in no phase advance or even a delay in the circadian rhythm.
Taking melatonin too late in the evening or in high doses can worsen DSPD by delaying your sleep phase. Timing is more critical than dose.
ModerateRefutesMEDIUM confidence
When too high a dose is administered and when it is given too late with respect to endogenous melatonin onset, this might result in melatonin levels persisting through the early morning. This could even result in delaying DLMO instead of advancing it!
Why this rating
Theoretical explanation based on phase-response curves and dose/timing interactions.
Source
The Use of Exogenous Melatonin in Delayed Sleep Phase Disorder: A Meta-analysis
Ingeborg M. van Geijlswijk et al. · SLEEP · 2010
DOI 10.1093/sleep/33.12.1605
Meta-analysis · 9 studiesCited 264×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Exogenous melatonin advances sleep-wake rhythm and endogenous melatonin onset in patients with Delayed Sleep Phase Disorder (DSPD) when administered chronobiologically timed (approximately 5 hours prior to Dim Light Melatonin Onset).Good
- Melatonin administration significantly reduces sleep-onset latency (SOL) in children with DSPD, but this effect is not statistically significant in adults.Good
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