Free Valproate, Saliva — Mass Concentration
Measures the amount of free, pharmacologically active valproate in saliva to help assess exposure and guide valproate therapy.
["This test estimates the active valproate level in saliva, but results must be interpreted with your dose, timing, symptoms, and other clinical findings."]
Key facts at a glance
- LOINC
- 15375-9
- Short code
- Valproate Free Sal-mCnc
- Synonyms
- Valproate Free Sal-mCnc
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 44
- Ref high
- 147
- Critical range
- — – 151 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84075
- SNOMED
- 27550007
- 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
What is this test?
This test measures the concentration of free valproate in saliva. Free valproate is the portion not bound to proteins and is responsible for the medicine's therapeutic effects.
Why might I need this test?
A clinician may order this test to help monitor valproate treatment when seizures or other symptoms are not well controlled, side effects are concerning, or medication exposure may have changed. It may also be used to assess adherence or the effects of other medicines on valproate.
How is the test performed?
A saliva sample is collected and analyzed in a laboratory. The result reports the concentration of free valproate, and the laboratory may provide collection-specific instructions for the saliva specimen.
How do I prepare for the test?
Collect the sample at the time specified by your clinician and record when you last took valproate. Follow the laboratory's instructions about eating, drinking, rinsing your mouth, and avoiding dental products immediately before collection, and do not change your medication unless your clinician advises you to do so.
Reference range
Adult: 44-147 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Salivary free valproate
Frequently asked questions
What is the difference between free and total valproate?
Does a low result mean I am not taking enough valproate?
Can I take my valproate normally before 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 17, 2026. · Read our editorial policy