Substances - Fentanyl: How Long Does It Stay in Your System?
Fentanyl has a shorter detection window than many opioids due to its rapid metabolism, but duration varies significantly by test type, dose, and frequency of use.
Fentanyl Half-Life and Metabolism
Fentanyl has a half-life of 2-4 hours for IV administration, though this can extend to 7-12 hours for transdermal patches. It is metabolized primarily in the liver into norfentanyl, the main metabolite detected in urine tests. Note that standard opioid immunoassay panels may not detect fentanyl; specific fentanyl testing is often required.
Detection Windows
| Test Type | Detection Window |
|---|---|
| Urine | 24-72 hours (occasional); up to 4 days (heavy use) |
| Blood | 5-48 hours |
| Saliva | 1-4 days |
| Hair | Up to 90 days |
Getting Help in New Jersey
If you or someone you love is struggling with fentanyl, please reach out to Archangel Centers at (732) 889-5400. Our admissions team is available 24/7. We serve Tinton Falls, Monmouth County, and surrounding areas of New Jersey. Most major insurance plans accepted.