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Oxycodone Concentration in Serum (Free)

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

This test measures the amount of free (unbound) oxycodone in your blood serum. Free drug levels help assess how much of the medication is actively available in your bloodstream.

Quick summary

["Understanding your free oxycodone levels can help doctors monitor your response to treatment and adjust your dose if needed."]

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

Key facts at a glance

LOINC
97295-0
Short code
oxyCODONE Free TissCo Ql Scn
Synonyms
oxyCODONE Free TissCo Ql Scn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
screen
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 This Test Is Done

Your healthcare provider may order this test if you’re taking oxycodone for pain management and want to ensure the medication is working effectively. Free drug levels are particularly important because they reflect the portion of the drug that can cross cell membranes and exert its effects in your body.

What to Expect Before the Test

No special preparation is needed for this test. You’ll provide a blood sample, usually drawn from a vein in your arm. The process is quick and typically done in a clinic or lab setting.

What the Results Mean

Results show the concentration of free oxycodone in your blood. While reference ranges vary by lab, higher levels may indicate adequate pain control or potential overdose risk, depending on your dose and medical history. Your provider will interpret these results in the context of your overall health and treatment plan.

Common Reasons for Testing

This test is often used to evaluate therapeutic drug monitoring (TDM) in patients on long-term oxycodone therapy. It helps identify whether your dose is too high or too low, ensuring safety and effectiveness.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Free Oxycodone Level

Frequently asked questions

What does my free oxyccodone level tell my doctor?
Your free oxycodone level helps your doctor assess how much of the medication is actively circulating in your blood. This is critical for managing pain, preventing overdose, and avoiding side effects like respiratory depression. Free drug levels also account for how your body processes and binds the drug, which can differ from total drug levels.
Why is free oxycodone testing different from total oxycodone testing?
Free oxycodone testing focuses specifically on the unbound portion of the drug, which is the part that can interact with your body’s receptors to produce effects. Total oxycodone testing includes both free and bound drug, which may not be as clinically relevant for monitoring pain relief or toxicity.
Can I influence my free oxycodone level?
Yes, factors like your liver function, protein levels in your blood, and other medications you take can affect how much of the drug is free. Your doctor may adjust your dose based on these results to optimize safety and effectiveness.
  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