Half-life ≈ 5 hours · why you can't sleep
☕ Caffeine in Your Blood
Log what you drank and when — phin coffee, bạc xỉu, milk tea, Red Bull… — and watch the caffeine curve in your bloodstream drawn live: absorption peak after ~45 minutes, then exponential decay with a ~5-hour half-life. See exactly how much is still in you right now, and whether you'll be under the 100 mg sleep threshold by bedtime.
1 · What did you drink?
2 · Your caffeine curve today
Model: one-compartment with ~45-min absorption ramp and adjustable half-life (4–6 h typical for adults; slower if pregnant or on some medications). Reference lines: 400 mg/day guidance for healthy adults and ~100 mg near bedtime often disturbs sleep (EFSA/FDA guidance). Figures are averages per serving — an estimate, not medical advice.