How long cannabis stays in urine
THC leaves the body as metabolites. The main one is THC-COOH (11-nor-9-carboxy-THC). Urine holds this metabolite longer than blood, oral fluid, or sweat.
How to Pass a Urine Test for Cannabis
Detection windows at the standard 50 ng/mL cutoff:
how long for thc to leave urine
- One-time use: 3 days.
- Use 2 to 4 times per week: 5 to 7 days.
- Use most days: 10 to 15 days.
- Long-term heavy use, concentrates or edibles: 30 days or more.
These are ranges, not guarantees. A test with a 20 ng/mL or 15 ng/mL cutoff extends each window.
Cutoffs set the window
An immunoassay screen uses 50 ng/mL for THC-COOH. Confirmation by GC-MS or LC-MS/MS uses 15 ng/mL. A lab that reports at the lower cutoff finds the metabolite for more days. Some employers screen at 20 ng/mL or 25 ng/mL. Ask which cutoff applies.
Cannabis Urine Detection Time Chart: What You Need to Know
What changes your result
Four factors drive the number:
- Frequency and amount. THC accumulates in fat tissue with repeat use.
- Potency. Concentrates and edibles carry more THC than flower.
- Body fat and metabolism. Fat releases the metabolite back into blood over weeks. Slow metabolism keeps levels higher.
- Hydration and kidney function. Urine volume affects concentration, not the amount stored.
Water lowers the concentration in one sample. Labs measure creatinine and specific gravity to flag dilute samples. A dilute sample often counts as a refusal or triggers a retest.
Other tests compared
Blood and plasma: 1 to 2 days for THC-COOH, longer with frequent use. Oral fluid: 24 hours to 3 days. Hair: up to 90 days. Urine sits below hair and above blood and saliva in length.
Secondhand smoke
Secondhand cannabis smoke can appear in urine at low cutoffs. Documented positives come from closed rooms with heavy smoke and no ventilation. At 50 ng/mL the risk is close to zero. At 15 ng/mL it rises.
What no test can predict
No test gives your own clearance date. Body fat, liver enzymes, dose, and history vary per person. A positive result confirms exposure. It does not measure impairment or the hour of use. Legal status does not change the result. Cannabis from a licensed store produces the same metabolites as cannabis from any other source.
Products sold to beat a test
Detox drinks, niacin, vinegar, creatine, and herbal teas show no evidence of clearing THC-COOH. Niacin at high doses causes liver damage. Substituted or synthetic urine carries legal risk, and labs check pH, creatinine, and temperature.