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Opioid-related substance concentration (serum/plasma)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of opioids in your blood or plasma, which helps track whether you’re using opioids for pain management—either starting a new prescription or continuing an existing one.

Quick summary

This test helps monitor opioid use to ensure safety and effectiveness.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
106714-9
Short code
DATEPRNOPIOIDINITIATEDORCONTINUED
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
cms-assessment
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you’re newly prescribed opioids or if you’re continuing long-term opioid treatment. It helps assess blood levels to prevent overdose risks and ensure the medication is working as intended.

What Does the Test Measure?

The test detects specific opioids (like morphine, oxycodone, hydrocodone, or fentanyl) in your blood or plasma. The results may vary depending on the type of opioid you’re taking and how your body processes it.

How Is the Test Performed?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab where it’s analyzed using a sensitive method (often immunoassay or mass spectrometry) to measure opioid levels.

What Do the Results Mean?

Results are typically reported as a concentration (e.g., micrograms per milliliter). While reference ranges can vary by lab, higher-than-expected levels may signal misuse, overdose risk, or improper dosing. Always discuss results with your provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: This test plays a critical role in opioid management by helping providers adjust dosages, detect misuse, or identify potential health risks associated with long-term opioid use.

Short name

Opioid Level (Serum/Plasma)

Frequently asked questions

Will I Feel Pain or Discomfort During the Blood Draw?
You may feel a slight pinch when the needle is inserted, but most people describe it as mild. The area may tingle or bruise slightly afterward. Your provider can use a numbing cream if needed.
How Long Until I Get My Results?
Results are usually available within 1–3 business days, depending on lab processing times. Your provider will contact you once they’re ready to review them.
Can I Eat or Drink Before the Test?
You can eat and drink normally before the test, as it’s a blood draw and doesn’t require fasting unless specified by your provider.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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