How long does THC stay in the body?
THC is detectable in blood 3–24 hours after use, in urine 3–7 days for occasional users and up to 30–90 days for daily users. Hair testing can detect THC metabolites for several months. Times depend on dose, frequency and body fat.
Key facts
- Blood: 3–24 hours after use
- Urine (occasional): 3–7 days
- Urine (daily): 30–90 days
- Saliva: 6–72 hours
- Hair: up to 3 months per cm
Detailed answer
THC is metabolised in the liver to THC-COOH and stored in fatty tissue. Detection windows differ sharply between tests: **Blood:** psychoactive effect 1–5 h; THC 3–24 h, THC-COOH much longer. **Urine (most common):** 3–7 days for single/occasional use, 7–21 days for regular use, 30–90 days for heavy daily use. Typical cut-off: 50 ng/mL THC-COOH. **Saliva:** 6–24 h, up to 72 h in chronic users. **Hair:** metabolites detectable up to 3 months per cm of hair length. Factors that extend detection: high body-fat percentage, high THC doses, daily use, slow metabolism, low hydration and physical activity.