Clearhead is an educational harm-reduction tool. It helps you understand — privately and offline — how long a substance is likely to affect you and when those effects fade, so you can be more aware and make safer decisions. It does not encourage use, give dosing advice, or tell you it is safe to drive. It exists to replace guesswork and recovery myths with published pharmacology.

WHY CLEARHEAD IS DIFFERENT
Unlike products that promise to speed things up, Clearhead just shows the evidence. It is built on published pharmacology and is honest about its limits:

• Time-based, not concentration-based. For cannabis, blood concentration barely predicts impairment (R² ≈ 0.03). Clearhead models a time-based recovery curve calibrated on real driving-impairment and population PK studies — not a number that means nothing.
• It cites its science. An in-app "How it works & sources" page lists the primary studies behind every estimate.
• It busts myths. Exercise, sweating and "drinking lots of water" do NOT speed up how fast your body clears a substance — and crash-dieting can make THC linger longer. Clearhead says so, with sources.
• It warns where it matters. Mixing depressants — opioids or benzodiazepines with alcohol — is where people die. Clearhead flags dangerous combinations and explains naloxone, instead of giving a false green light.

WHAT IT COVERS
A clear, consistent estimate for each of six categories:
• Cannabis (THC) — impairment recovery curve, plus blood, saliva and urine windows
• MDMA / ecstasy — effect duration, redose risk, recovery
• Cocaine — route, binge, alcohol→cocaethylene
• Stimulants — methamphetamine and amphetamine
• Benzodiazepines — Xanax/Neurol, Lexaurin, Rivotril, Valium and more
• Opioids — tramadol, codeine, oxycodone, morphine, buprenorphine, methadone, fentanyl and more, with respiratory-risk and naloxone guidance

It accounts for your body (age, sex, build), how and when you took it (including "I took it yesterday"), how often you use, and dangerous combinations.

ABSOLUTE PRIVACY
Clearhead collects nothing. No account, no servers, no analytics, no ads, no trackers. Everything stays on your device and works fully offline. Nothing you enter ever leaves your phone.

IMPORTANT
Clearhead is educational harm-reduction information only. It is an ESTIMATE, not a measurement — your body and the dose both vary. It is not medical advice, not a diagnostic tool, and never permission to drive or to use any substance. If you are in doubt, do not drive; if someone is in danger, call emergency services. The safest choice is always none.

Rated 18+. Clearhead does not sell or facilitate the sale of any substance.