Caffeine Half Life

Caffeine Half Life helps you estimate how caffeine leaves your system over time — so you can make more informed choices about sleep and energy.

Highlights
- Personalized elimination curve using your profile (e.g. smoking, pregnancy, oral contraceptives) when you choose to provide them
- Sleep-readiness estimates based on your bedtime and caffeine threshold — approximate only
- Apple Health: optional read/write for dietary caffeine, plus HRV correlation on the chart so you can spot patterns (you control permissions)
- Widgets and Apple Watch complications for quick glances — including a trend graph complication
- Interactive chart — drag to inspect caffeine levels and HRV at any time of day

How it works
The app uses a simplified pharmacokinetic model (Bateman equation) to estimate caffeine absorption and elimination based on your personalized half-life. Factors like age, BMI, activity level, smoking, pregnancy, and oral contraceptives adjust the half-life up or down from the ~5-hour population average.
Important: This app is for general wellness and educational purposes. It is not medical advice and not a medical device. All estimates are approximate — individual metabolism varies. Consult a healthcare professional for health decisions.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/