An honest tool, not a shortcut.
Clearhead replaces guesswork and marketing with published science — a time-based recovery model, honestly presented and openly cited.
Time, not a meaningless number.
For cannabis, blood concentration barely predicts impairment (R²≈0.03). Clearhead models a time-based recovery curve calibrated on real driving-impairment and population pharmacokinetic studies — for six substance families.
It does not encourage use, give dosing advice, or tell you it's safe to drive. It exists to help people who do use substances understand what's happening in their body.
Everything runs on your device. We never see what you type.
- Time, not a meaningless numberRecovery modelled over time, not a blood value that means nothing.
- It cites its sourcesAn in-app page lists the primary studies behind every estimate.
- It warns where it mattersFlags dangerous combinations and explains naloxone.
Built to be trusted.
Not a detox product, not a promise to speed things up — just the evidence.
Science-backed
Calibrated on real driving-impairment and population PK studies — Dolder, McCartney, Kolbrich, Schepers and more.
Myth-busting
Exercise, sweating and "drinking water" don't speed up how fast your body clears a substance. We say so — with sources.
Live tracking
Log a dose and watch a live countdown until the effects likely fade — across multiple doses at once.
Brutally private
No account, no analytics, no ads, no trackers. Everything stays on your device and works offline.
Safety first
Combination-danger warnings and naloxone guidance are always free — never hidden behind a paywall.
Retroactive timing
Took it hours ago? Yesterday? Enter when — the estimate adjusts, including blood, saliva and urine windows.