Caffeine and Sleep: How Late Is Too Late?
Caffeine lingers for hours. Learn the half-life, the six-hour study, hidden sources in mg, decaf facts and a two-week test to find your own cut-off.
Topic · 3 articles
Food, drink & sleep
What you eat and drink in the afternoon and evening has a direct line to how you sleep. Caffeine lingers for hours, alcohol fragments the second half of the night, and heavy late meals can make lying down uncomfortable.
This section separates what the evidence supports from what is mostly marketing.
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Quick answers
How late is too late for caffeine?
Caffeine has a half-life of roughly 5 hours for many adults, so a mid-afternoon coffee can still be active at bedtime. Many people sleep better when they stop caffeine 6 to 8 hours before bed, though sensitivity varies widely.
Does alcohol help you sleep?
Alcohol can make you fall asleep faster, but it tends to fragment sleep later in the night, reduce REM sleep, and worsen snoring and sleep apnea. It is not a reliable sleep aid.
All articles in Food, drink & sleep
Does Alcohol Help You Sleep? Why a Nightcap Backfires
Alcohol makes you fall asleep faster, then breaks up the second half of the night: less REM, more waking, worse snoring and apnea. What to do instead.
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