Fentanyl Concentration in Whole Blood by High-Performance Liquid Chromatography (HPLC)
This test measures the amount of fentanyl, a powerful opioid pain medication, in your blood. It helps assess drug exposure, especially in cases of overdose or monitoring therapeutic levels.
["This test helps doctors track opioid levels to ensure safe dosing and detect potential risks of overdose."]
Key facts at a glance
- LOINC
- 105204-2
- Short code
- Norfentanyl Bld LC/MS/MS-mCnc
- Synonyms
- Norfentanyl Bld LC/MS/MS-mCnc
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 0
- Ref high
- 100
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- lc-ms-ms
- CPT
- 83721
- SNOMED
- 113079007
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you’re taking fentanyl for pain management, if you’ve experienced symptoms of opioid overdose (such as slowed breathing, confusion, or unconsciousness), or if you’re suspected of fentanyl exposure through other routes (e.g., illegal use). It may also be used in medical settings like emergency rooms or intensive care units to monitor patients on fentanyl-based medications.
What to Expect Before the Test
No special preparation is needed for this test. You’ll have a small needle inserted into your arm to draw a sample of whole blood. The process is quick and typically painless. If you’re taking blood from a vein in your arm, you may feel a slight pinch, but most people tolerate it well.
What Happens During the Test
The blood sample is collected in a tube and sent to a lab for analysis using high-performance liquid chromatography (HPLC). This method separates and measures fentanyl precisely. Results are usually available within 24 to 48 hours, depending on lab processing times.
What the Results Mean
Results show the concentration of fentanyl in your blood. While reference ranges can vary by lab and clinical context, higher levels may indicate recent opioid use, overdose risk, or therapeutic monitoring needs. Your doctor will interpret results in relation to your medical history and symptoms.
Reference range
Optimal: <100 mg/dLN/A
Fasting for 12-14 hours preferred. Water is permitted. Avoid alcohol for 24 hours before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Fentanyl Blood Level
Frequently asked questions
How long does it take to get the results of this test?
Can I eat or drink before this test?
Is there any risk or discomfort associated with this test?
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