Skip to content

Valproate Drug Level (Serum)

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

A blood test that measures the amount of valproate in your body. It is used to help monitor treatment effectiveness and medication safety.

Quick summary

["This test shows how much valproate is in your blood and can help your clinician adjust the dose safely."]

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

Key facts at a glance

LOINC
4458-6
Short code
Valproate Dose
Synonyms
Valproate Dose
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?

A valproate level measures the concentration of valproate, a medicine used for seizures and certain other conditions, in a blood sample. The result helps your clinician assess whether the current dose is appropriate.

Why might I need this test?

Your clinician may order this test when starting or changing valproate, when seizures are not well controlled, or if you have symptoms that could be related to too much medicine. It may also be checked to assess safety in people with liver problems or other health conditions.

How is the test performed?

A small blood sample is drawn from a vein and sent to a laboratory. The laboratory measures the valproate concentration using a validated testing method.

How do I prepare for the test?

Follow your clinician's instructions about when to take valproate before the blood draw. Because medication levels can vary, the test is often scheduled at a consistent time relative to your dose. Do not change or stop your medication unless your clinician tells you to do so.

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

Does this test tell me how well valproate is working?
It shows how much valproate is in your blood at the time of testing. Your clinician considers the result together with seizure control and side effects to assess treatment.
Should I take my usual valproate dose before the test?
Usually, you should keep taking valproate as prescribed unless your clinician gives different instructions. Tell the laboratory when you took your last dose so the result can be interpreted accurately.
Are there risks from having a valproate level checked?
The test requires a routine blood draw. Some people may experience minor bruising, soreness, or rarely, infection at the needle site.
  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