Research
Hormonal
Caffeine increases sleep onset latency by approximately 9 minutes and wake after sleep onset by approximately 12 minutes.
Caffeine makes it harder to fall asleep and stay asleep. Expect to take about 9 minutes longer to fall asleep and spend 12 minutes more awake during the night. This fragmentation reduces overall sleep efficiency by 7%.
WeakSupportsHIGH confidence
Caffeine consumption reduced total sleep time by 45 min and sleep efficiency by 7%, with an increase in sleep onset latency of 9 min and wake after sleep onset of 12 min.
Why this rating
Meta-analysis of 19-20 studies for these specific metrics.
Source
The effect of caffeine on subsequent sleep: A systematic review and meta-analysis
Carissa Gardiner et al. · Sleep Medicine Reviews · 2023
DOI 10.1016/j.smrv.2023.101764
Meta-analysis · 24 studiesCited 273×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Caffeine consumption reduces total sleep time by an average of 45 minutes and decreases sleep efficiency by 7%, with the magnitude of sleep loss increasing as the dose increases and the time of consumption approaches bedtime.Weak
- Caffeine consumption alters sleep architecture by increasing the duration and proportion of light sleep (N1) and decreasing the duration and proportion of deep sleep (N3/N4).Weak
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