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Valproic Acid Level, Blood

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

A blood test that measures the amount of valproic acid in your body, helping your clinician confirm that an anticonvulsant dose is appropriate and safe.

Quick summary

["This test helps determine whether your valproic acid dose is effective and whether adjustments may be needed."]

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

Key facts at a glance

LOINC
74260-1
Short code
HEDIS 2014 Valp Acid
Synonyms
HEDIS 2014 Valp Acid
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
44
Ref high
147
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 valproic acid level test measures the amount of valproic acid in a blood sample. Valproic acid is a prescription medicine used to control seizures and may also be used for mood stabilization or migraine prevention.

Why might I need this test?

Your clinician may order this test to check whether you are taking the correct dose, assess treatment effectiveness, investigate side effects, or identify possible drug interactions. It may also be checked when starting or changing valproic acid therapy.

How is the test performed?

A blood sample is collected and analyzed in a laboratory to determine your valproic acid concentration. The result is interpreted alongside the dose you take, the timing of your last dose, your symptoms, and other relevant medications.

How do I prepare for the test?

Take valproic acid exactly as prescribed and tell your clinician when you took your last dose. Do not stop or change the dose on your own, because abrupt changes can increase seizure risk; follow any specific timing instructions provided for the blood draw.

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

Valproic Acid Level

Frequently asked questions

Is a valproic acid level the same as a liver function test?
No. The valproic acid level measures the amount of medication in the blood, while liver function tests assess how well the liver is working. Your clinician may order both because valproic acid can rarely cause liver problems.
Does the time of my last dose affect the result?
Yes. The concentration changes over time after a dose, so the blood sample is often drawn at a specific interval. If you are unsure when to take the test, ask your clinician or laboratory for instructions.
What should I do if my level is too high or too low?
Do not change your dose yourself. Contact the clinician who prescribed valproic acid so the result can be reviewed with your symptoms, other medicines, and relevant laboratory tests.
  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