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Valproate, Urine — Mass Concentration

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

This test measures the amount of valproate, the active form of valproic acid, in a urine sample. It is used less often than blood testing and may help evaluate medication exposure.

Quick summary

["Urine valproate measures medication exposure, but results can vary with hydration and urine collection timing."]

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

Key facts at a glance

LOINC
17762-6
Short code
Valproate Ur-mCnc
Synonyms
Valproate Ur-mCnc
Category
liver
Sample
urine
Container
Sterile urine container
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
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test measures the concentration of valproate, the active form of the seizure medicine valproic acid, in urine. Blood valproate testing is more commonly used for routine monitoring.

Why might I need this test?

A urine valproate test may be used to assess valproic acid exposure, investigate possible toxicity, or help evaluate medication use. It may occasionally be used in situations when a blood sample cannot be obtained.

How is the test performed?

A urine sample is collected and tested in a laboratory to determine the amount of valproate present. The result may be reported as a mass concentration or compared with a urine creatinine measurement to account for differences in concentration.

How do I prepare for the test?

Follow any collection instructions provided by your healthcare professional, including whether a timed or first-morning urine sample is required. Continue taking valproic acid as prescribed unless your clinician tells you otherwise, and tell the laboratory about your dose and the time of your last dose.

Reference range

Adult: 44-147 U/LN/A

Specimen: urine

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

Urine valproate

Frequently asked questions

Is a urine valproate test the same as a blood test?
No. A blood valproate level is the usual test for monitoring valproic acid therapy. Urine testing may provide additional information but is affected by hydration, collection timing, and kidney function.
What might cause a high urine valproate result?
Possible causes include taking the medicine shortly before collection, a higher dose, reduced kidney clearance, or medication toxicity. A healthcare professional should interpret the result in context rather than relying on the urine level alone.
Can I change my valproic acid dose based on this result?
No. Do not change or stop valproic acid without medical guidance, because abrupt changes can increase the risk of seizures or other serious reactions. Ask your prescriber to review the result with your other laboratory findings and symptoms.
  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