Built on real pharmacokinetics.
See if coffee will cost you sleep.
cafein is a caffeine tracker for people who love coffee and refuse to compromise on sleep. Pharmacokinetics-powered. Cortisol-aware. Apple Health synced.
Coming soon
Drink coffee on purpose.
Watch a real pharmacokinetics model show how every cup ripples through your day.
Will tonight’s coffee cost you sleep?
A real pharmacokinetics model projects how much caffeine you’ll likely still have in your bloodstream at bedtime — so you can make the call before you sip.
Work with your natural cortisol
Your cortisol naturally peaks in the first hour after waking, which can blunt how strongly caffeine hits. cafein highlights the window where your first cup tends to land hardest.
Simulate before you sip
Thinking about a 4 pm espresso? Test combinations without committing. See how that hypothetical second coffee changes your bedtime number, then decide.
Synced to Apple Health or Health Connect
Every cup you log writes to Apple Health (and Health Connect on Android, when it ships). Your data stays yours — exportable any time, ready to share with your doctor or AI assistant.
See it in action.
The whole app fits in five screens. Each one tells you something coffee apps usually skip.
Tracking made simple.
Tracking caffeine has never been this simple.
Save money with cafein Pro.
Most users skip one or two unnecessary coffees a week after seeing their curve. That pays for Pro many times over. Protect your sleep with cafein Pro.
Unlimited simulations
Test any combo, any time. No daily cap.
Export to AI as CSV
Feed your history into ChatGPT, Claude, or Gemini.
Save money on unnecessary coffees
One fewer coffee a week pays for Pro many times over.
Free covers up to 5 coffees a day and full Apple Health sync. No signup required.
Coming soon