Fentanyl

Interpretation

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

Metabolites

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

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.