This tool gives general information based on
the research summarised in Afternoon Caffeine and Sleep: How Late Is Too Late. It is not a medical
device, does not diagnose, and does not replace advice from your clinician.
What this is based on
Every output names at least one verified PubMed source.
Gardiner C, Weakley J, Burke LM, et al. The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Sleep Med Rev. 2023;69:101764. PMID 36870101 Systematic review and meta-analysis of caffeine and subsequent sleep. · weight 1.0 · Caffeine taken before sleep lengthens sleep onset latency and reduces total sleep time; effects are dose- and timing-dependent.
Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med. 2013;9(11):1195-1200. PMID 24235903 Randomized, double-blind, placebo-controlled crossover trial (n=12); 400 mg caffeine at 0, 3 or 6 h before bed. · weight 0.8 · 400 mg caffeine taken even 6 hours before bedtime measurably reduced objective sleep time compared with placebo.
Limits: Half-life values are population averages, not a measurement of you. Genetics, pregnancy, smoking and some medicines shift them a lot. This is a starting rule, not a prescription.
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Text only, generated locally.
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