Research

Hormonal

Caffeine consumption (particularly >200 mg) disrupts sleep quality and quantity by reducing melatonin metabolites and shifting sleep architecture, leading to next-day performance deficits.

If you consume caffeine, be aware that it can disrupt your sleep even if you stop 6 hours before bed. This disruption leads to next-day performance deficits. To mitigate this, limit caffeine intake to early morning hours or reduce total daily dosage, especially if you are sensitive to sleep loss.

GoodRefutesHIGH confidence
Caffeine consumption by day causes a reduction in 6-sulfatoxymelatonin (the main metabolite of melatonin) on the ensuing night, which is one of the mechanisms by which sleep is interrupted.
Frances O’Callaghan et al. · Risk Management and Healthcare Policy · 2018

Why this rating

Supported by multiple controlled studies (Drake et al., Landolt et al.) showing significant sleep disturbance even 6 hours prior to bedtime.

Source

Effects of caffeine on sleep quality and daytime functioning

Frances O’Callaghan et al. · Risk Management and Healthcare Policy · 2018

DOI 10.2147/rmhp.s156404

narrative_reviewCited 222×
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DOI resolved against Crossref · corpus check 2026-06-10

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