Drug Detection Windows
How long drugs stay detectable in your system depends on the test type, substance, frequency of use, and individual factors.
Important: Detection times are estimates and vary significantly based on individual metabolism, body composition, hydration, frequency of use, and potency of the substance.
Detection Windows by Test Type
| Substance | Urine | Blood | Saliva | Hair |
|---|---|---|---|---|
| Marijuana (THC) Single use |
3 days | 1-2 days | 24 hours | 90 days |
| Marijuana (THC) Chronic use |
30+ days | 7 days | 72 hours | 90 days |
| Cocaine | 2-4 days | 1-2 days | 1-2 days | 90 days |
| Opiates (Heroin, Codeine, Morphine) | 2-4 days | 1-2 days | 1-4 days | 90 days |
| Oxycodone, Hydrocodone | 2-4 days | 1-2 days | 1-4 days | 90 days |
| Amphetamines | 1-4 days | 1-2 days | 1-3 days | 90 days |
| Methamphetamine | 3-5 days | 1-3 days | 1-4 days | 90 days |
| Benzodiazepines Short-acting |
3-5 days | 1-2 days | 1-10 days | 90 days |
| Benzodiazepines Long-acting |
4-6 weeks | 3-7 days | 1-10 days | 90 days |
| PCP | 7-14 days | 1-3 days | 1-3 days | 90 days |
| Barbiturates Short-acting |
2-4 days | 1-2 days | 1-7 days | 90 days |
| Barbiturates Long-acting |
2-3 weeks | 3-7 days | 1-7 days | 90 days |
| MDMA (Ecstasy) | 2-4 days | 1-2 days | 1-3 days | 90 days |
| Methadone | 3-5 days | 1-2 days | 1-4 days | 90 days |
| Fentanyl | 1-3 days | 12-24 hours | 1-4 days | 90 days |
Factors Affecting Detection Times
- Frequency of use: Chronic users retain drugs longer
- Dosage: Higher doses take longer to clear
- Metabolism: Faster metabolism = shorter detection
- Body fat: THC stores in fat cells
- Hydration: Affects urine concentration
- Drug potency: Stronger drugs may linger longer
- Liver/kidney function: Affects drug metabolism
Test Type Considerations
- Urine: Most common; detects recent to moderate past use
- Blood: Short window; shows current impairment
- Saliva: Very recent use; hard to cheat
- Hair: Long-term history; won't show recent use (last 5-7 days)
Understanding Half-Life
A drug's "half-life" is the time it takes for half of the drug to be eliminated from your body. Most drugs require 4-5 half-lives to be fully eliminated. This is why detection windows vary so much between substances:
- Short half-life: Cocaine (1 hour), Heroin (3-5 minutes for 6-MAM)
- Medium half-life: Marijuana (20-30 hours for infrequent users), Amphetamines (10-12 hours)
- Long half-life: Diazepam/Valium (20-80 hours), Marijuana (3-13 days for chronic users)
Need More Information?
Learn more about specific drug tests or find a testing center near you.