randomized crossover trial · n=12
Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed
Journal of Clinical Sleep Medicine · 2013
Open PubMed recordDOI 10.5664/jcsm.3170substances
Caffeine after lunch is harmless
Grade A · StrongHuman reviewed
What people say
“I can drink caffeine in the afternoon and still sleep normally.”
What the evidence says
Grade A · StrongIn a small controlled study, caffeine taken six hours before bed reduced total sleep time and changed sleep measures, even when people did not fully notice the disruption.
Research record
What this verdict is based on
Sources are linked for inspection. Study results are summarized for general information, not personal medical direction.