Marijuana detection windows at a glance
| Test type | Approximate detection window |
|---|---|
| Saliva (oral fluid) | Up to ~24–72 hours after use |
| Blood | A few hours up to ~1–2 days (longer for heavy users) |
| Urine | ~3 days (single use) to 30+ days (daily/heavy use) |
| Hair follicle | Up to ~90 days |
Why the urine range is so wide
Unlike most drugs, THC is stored in body fat and released slowly over time. For someone who uses once, a urine test may be clear in a few days. For a daily or long-term user, THC metabolites can keep showing up for a month or more after the last use. Frequency of use is the single biggest factor.
What affects how long THC lasts
- How often you use — occasional vs. daily is the biggest driver
- Potency and amount — higher-THC products build up faster
- Body fat — THC is stored in fat, so more storage means longer detection
- Metabolism and activity — everyone processes it at a different rate
- The test and its cutoff — different tests and thresholds change the outcome
Which test is right for your situation
If you need to show recent use or abstinence over a short window, a urine test or saliva test is usually the right call. When a court or employer wants a longer look-back, a hair follicle test can show a pattern up to about 90 days. Not sure which one applies to you? We'll help you choose.
