Urine drug testing • THC / cannabis

Cannabis detection times in urine (THC urine test windows)

“How long does cannabis stay in urine?” depends on your use pattern, the test cutoff (often 50 ng/mL for screening), and how your body processes THC metabolites. This guide explains typical urine detection windows, why they vary, and what urine test results can—and can’t—tell you.

Important: We do not provide instructions to tamper with or “beat” drug tests. This content is for education and recovery support.
Written by: A Road To Recovery Rehab Editorial Team
Clinically reviewed by: Dr. James Stanford, MD
Last updated:
THC detection times (50 ng/mL) All THC test types

At a glance: typical cannabis detection times in urine

These are general ranges. Your timeline can be shorter or longer depending on cutoff level and individual factors.

Use pattern Commonly cited urine detection window (approx.) Notes
Single / one-time use ~1 to ~5 days (varies by cutoff and method) Some clinical references cite ~4–5 days; some 50 ng/mL screening windows can be shorter in controlled data.
Casual / occasional use ~1 to ~10 days Frequency, potency, and the cutoff (20 vs 50 vs 100) can meaningfully change the window.
Daily use ~5 to ~21 days (sometimes longer) Repeated use can increase persistence due to metabolite accumulation.
Chronic heavy daily use ~30 days is commonly cited; longer cases are reported Individual differences, body composition, and test sensitivity drive big variability.

Most important takeaway: There’s no single “guaranteed” number of days for everyone.

What urine tests measure (THC vs metabolites)

Most urine drug tests do not measure the THC that causes intoxication. They primarily detect a THC metabolite (often described as THCA/THC‑COOH).

Important: A urine THC test generally indicates prior exposure, not current impairment.

Want a broader view? THC drug testing for urine, blood, hair, and saliva.

Why cutoffs (50 vs 15 vs 20) change detection time

The same person can test negative at one cutoff and positive at a more sensitive cutoff. That’s why “how long cannabis stays in urine” depends on the program and lab.

  • 50 ng/mL is a common initial screening cutoff.
  • 15 ng/mL is a common confirmatory cutoff in some regulated programs.
  • Some labs use 20 ng/mL (more sensitive) or 100 ng/mL (less sensitive).

What research reviews suggest: at a 50 ng/mL immunoassay cutoff, single-event detection can be relatively narrow in controlled settings. Lower cutoffs and confirmation testing can extend detection.

Related: Understanding the 50 ng/mL cannabinoid cutoff

What affects how long cannabis stays in urine?

Major factors include:

  • Frequency & duration of use (the biggest driver)
  • Potency + dose
  • Body composition (THC metabolites are fat-soluble)
  • Metabolism and overall health
  • Test cutoff + method (screen vs confirmation)
  • Urine concentration can vary day-to-day (which affects measured levels)

Note: Trying to manipulate a test can have serious consequences. We don’t provide tampering guidance.

Also relevant: Is cheating a drug test a good idea?

What urine THC tests can and can’t tell you

  • Can tell: whether cannabis metabolites were detected above a program’s cutoff.
  • Can’t reliably tell: the exact time of last use, how much was used, or whether someone is impaired right now.

If a result is disputed: ask whether confirmation testing was performed and how the program handles medical explanations (when applicable).

FAQ: cannabis detection times in urine

Is 50 ng/mL the “standard” THC urine cutoff?

It’s common, but not universal. Many programs use 50 ng/mL for screening; others may use 20 or 100 ng/mL depending on policy and lab.

Can secondhand smoke cause a positive urine test?

It’s generally considered unlikely at standard cutoffs in typical settings, though extreme, poorly ventilated exposure is sometimes discussed.

Can CBD lead to a THC positive?

Some CBD products contain THC (even if labeled “hemp”). Certain prescribed cannabinoid medications may also affect results. Disclose medications/supplements according to your program’s policy.

What if I keep using and can’t stop?

You’re not alone. Withdrawal, cravings, stress, and habit loops can make quitting hard. Treatment can help you stabilize and build a plan that sticks. Contact our team.

If quitting is hard, we can help

If cannabis is affecting your mood, sleep, motivation, relationships, or work—and you’re stuck in a quit/relapse cycle— a structured recovery plan can help.

Get started Talk to admissions

Related: How to stop smoking weed

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