Norfentanyl/Creatinine Ratio, Urine
A urine test that measures norfentanyl, a metabolite of fentanyl, relative to creatinine. It is used to help identify recent fentanyl exposure.
["Detecting norfentanyl in urine may indicate that the person has recently been exposed to fentanyl."]
Key facts at a glance
- LOINC
- 58382-3
- Short code
- Norfentanyl/Creat Ur
- Synonyms
- Norfentanyl/Creat Ur
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 86430
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures norfentanyl, a breakdown product of fentanyl, in a urine sample. The result is compared with the amount of creatinine in the same sample to help account for differences in urine concentration.
Why might I need this test?
Urine norfentanyl testing may be used in situations involving suspected drug exposure, substance-use treatment, workplace testing, or medical evaluation. A result can provide information about prior exposure but cannot by itself determine how much drug was taken or whether someone was impaired at the time of testing.
How is the test performed?
A urine specimen is collected and analyzed by the laboratory for norfentanyl and creatinine. The laboratory reports the amount of norfentanyl relative to the amount of creatinine as a ratio.
How do I prepare for the test?
Follow the collection instructions provided by the laboratory or healthcare professional. Fasting is generally not required, but the person collecting the sample should use the provided container and follow any instructions for collection timing and handling.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A detectable norfentanyl result may indicate recent exposure to fentanyl or a related medication. A negative result does not completely exclude exposure because the amount and timing of drug use and the speed of metabolism can affect detection. The result should be interpreted by a healthcare professional along with the clinical circumstances and, when appropriate, confirmatory testing.
Short name
Urine norfentanyl
Frequently asked questions
What does a urine norfentanyl result mean?
Why is the result divided by creatinine?
How long can norfentanyl remain detectable?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy