Substance guides
How long does Klonopin stay in your system?
Published July 1, 2025 · 6 min read · Updated April 2026
Reviewed for accuracy by licensed clinical professionals.
Klonopin (clonazepam) has a long half-life of 18-50 hours, making it detectable longer than short-acting benzos like Xanax.
Detection
Urine: 5-14 days for occasional use, up to 30 days for chronic heavy use. Detected on standard benzodiazepine panels. Blood: 2-3 days. Hair: up to 90 days.
Why so long
Clonazepam's long half-life plus its metabolite 7-aminoclonazepam create extended detection. Chronic users accumulate the drug, requiring weeks for full clearance.
Clinical note
Klonopin is commonly prescribed for seizure disorders and panic disorder. Its long half-life provides more stable blood levels than Xanax but also means longer withdrawal and detection.
Frequently asked questions
How long does Klonopin stay in urine?
5-14 days for occasional use, up to 30 days for chronic heavy use.
Is Klonopin stronger than Xanax?
Milligram for milligram they are roughly equivalent. Klonopin lasts much longer (18-50 hour vs 6-12 hour half-life).
Does Klonopin show on a drug test?
Yes. Detected on standard benzodiazepine panels.
Disclaimer: Informational only. Not medical advice. SAMHSA: 1-800-662-4357.