Caffeine half-life
Representative value5 hCaffeine model
Reported range1.5 h–9.5 hSource-dependent
After two half-lives25%Modeled remainder
Evidence record3 sourcesUpdated Jul 21, 2026
Relative starting point
100%
Every curve begins at 100%. No dose or measured body concentration is assumed.
X-axis: elapsed time. Y-axis: modeled percentage of the relative starting point remaining. The shaded band shows the reported half-life range. This is a mathematical visualization, not a personal concentration estimate.
Modeled remaining: 50.0%Half-life used: 5 h
What to notice
A practical five-hour caffeine curve that keeps modeled persistence separate from alertness and sleep quality.
EvidenceWhy this representative value is used
The linked NCBI Bookshelf chapter reports a mean plasma half-life of about 5 hours in healthy people and a 1.5-to-9.5-hour range.
Model limitsWhy persistence is not the same as effects
The normalized curve does not predict alertness, impairment, sleep, safety, or measured concentration.
Source trailOpen the studies, labeling, and supporting records
3 annotated references are attached to the complete profile.