• The presence of fentanyl or norfentanyl >LOQ indicates exposure to fentanyl within 3 days.


  • Fentanyl is metabolized primarily by oxidative N-dealkylation to norfentanyl.

    Fentanyl Norfentanyl

Confirmation Tests:

Approximate Detection Times

Fentanyl LOQ (ng/mL) Detection Time* up to
Fentanyl 0.2 3 days
Norfentanyl 1.0 3 days
*These are approximate detection times for the drug or metabolites in urine. The actual detection time depends on dose, frequency of use, and individual metabolism.