Genes Dictate If Caffeine Keeps You Up All Night

Caffeine typically remains in the system for 4-6 hours on average (half-life), but genetic variations make some people slow metabolizers who retain it up to 8-10 hours, leading to extended alertness and sleep disruption.

  • Variations in the CYP1A2 gene classify individuals as fast or slow caffeine metabolizers, affecting half-life.
  • Average 4-6 hours, but slow metabolizers retain caffeine longer, up to 8-10 hours, disrupting sleep.
MetricScientific ObservationImpact MagnitudeSource
Half-lifeAverages 4-6 hours, varies by CYP1A2 geneticsSlow metabolizers: up to 8-10 hours retentionLucas et al. (2022), Nutrients
Sleep QualityEvening intake disrupts latency and deep stagesProlonged alertness in slow metabolizersLucas et al. (2022), Nutrients
Clearance FactorsSmoking accelerates, contraceptives slow metabolismAlters personal sensitivityStudy findings on physiological influences
Genetic TestingCYP1A2 variants predict responseImproves timing for better sleepLucas et al. (2022), Nutrients