Caffeine and Sleep: When to Stop
Caffeine lingers in the body longer than most people think.
Half-life
Caffeine has a half-life of about five hours, so a 4 pm coffee leaves about half its caffeine in your system at 9 pm.
Effect on sleep
Caffeine taken six hours before bed can reduce sleep by an hour. It also makes sleep lighter even when you fall asleep easily.
Set a cutoff
Many people sleep better stopping caffeine at least eight hours before bed. Slow metabolisers and pregnant people should leave longer.
Try it: Caffeine Cutoff Calculator
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Caffeine has a half-life of about 5 hours. The plan assumes under 25 mg remaining at bedtime. Half-life varies with genetics, pregnancy and medication.
Educational content only. This article does not replace advice from a qualified health professional. Medical disclaimer.