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Caffeine Half-Life

Calculate how long caffeine remains in your body based on half-life factors like pregnancy, smoking, and liver function. See your personalized caffeine decay timeline.

Applications

Used by coffee drinkers to plan evening consumption, by pregnant individuals monitoring caffeine intake, and by anyone sensitive to caffeine who wants to understand how long effects may last.

The Formula

Uses the exponential decay formula: remaining = initial x 0.5^(time / halfLife). The half-life is adjusted based on individual factors: Adult (5h), Smoker (3h), Pregnant 1st trimester (12h), Pregnant 3rd trimester (18h), Oral contraceptives (10h), Liver impairment (15h).

Fun Fact: Caffeine is metabolized primarily by the CYP1A2 enzyme in the liver. This is why smoking (which induces CYP1A2) speeds up caffeine metabolism, while pregnancy and certain medications slow it down significantly.

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