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Valproate, Serum/Plasma — Concentration

Published: August 9, 2026Updated: August 17, 2026

A blood test that measures the amount of valproate in your blood to help monitor treatment effectiveness and the risk of medication toxicity.

Quick summary

["This test helps your clinician confirm that your valproate dose is appropriate and safe for you."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
72936-8
Short code
Valproate (neut) IgG SerPl Ql FC
Synonyms
Valproate (neut) IgG SerPl Ql FC
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
Method
flow-cytometry
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 valproate, the active form of the seizure medicine valproic acid, in a blood sample. It is used to assess medication exposure and help guide dosing.

Why might I need this test?

Your clinician may order it when starting or changing valproate, during routine monitoring, or if you have signs of possible medication toxicity. It may also be checked when there are concerns about missed doses, interactions with other medicines, or changes in medication clearance.

How is the test performed?

A blood sample is collected, and the laboratory separates serum or plasma and measures the valproate concentration using a validated laboratory method. The sample is usually collected at a time specified by your clinician.

How do I prepare for the test?

Continue taking valproate exactly as prescribed unless your clinician tells you otherwise. Tell the healthcare team when you last took a dose, because the timing of the blood draw can affect the result; fasting is generally not required.

Reference range

Adult: 44-147 U/LN/A

Specimen: serum

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

Valproate Level

Frequently asked questions

What does a valproate level measure?
It measures the concentration of valproate in your blood. Your clinician compares this result with your dose, symptoms, and overall health to assess whether treatment is appropriate.
How often is valproate monitored?
Testing frequency depends on your dose, clinical condition, other medicines, and laboratory guidance. It is often repeated after dosage changes or when toxicity, inadequate seizure control, or medication-interaction concerns arise.
What should I do if my result is unexpected?
Contact your prescribing clinician before changing your dose. The clinician may consider the timing of the sample, confirm the result, review interactions and organ function, and recommend any follow-up.
  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 17, 2026. · Read our editorial policy