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Gamma-Aminobutyric Acid/Creatinine Ratio, 24-Hour Urine

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

Measures the amount of gamma-aminobutyric acid (GABA) relative to creatinine in urine collected over 24 hours.

Quick summary

["This test measures urinary GABA relative to creatinine, which helps account for differences in urine concentration."]

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

Key facts at a glance

LOINC
56679-4
Short code
GABA/Creat 24h Ur-Rto
Synonyms
GABA/Creat 24h Ur-Rto
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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?

Gamma-aminobutyric acid, or GABA, is a signaling molecule in the brain and nervous system. This test measures GABA relative to creatinine in all urine collected during a 24-hour period.

Why might I need this test?

A 24-hour urine GABA measurement may be used in the evaluation of certain rare metabolic or nervous-system conditions. Your clinician will explain why this specialized test is appropriate for you.

How is the test performed?

You collect all urine for exactly 24 hours, beginning and ending at the times specified by the laboratory. The total volume is recorded, and a sample is sent for laboratory analysis.

How do I prepare for the test?

Follow the laboratory's collection instructions and record when the collection starts and ends. Stay hydrated, avoid losing urine from the collection container, and ask the laboratory whether refrigeration is required. Do not stop medications unless your clinician instructs you to do so.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Results must be interpreted with symptoms, medical history, medications, and other laboratory findings. An abnormal GABA or GABA-to-creatinine ratio may reflect altered GABA metabolism, intake, medication effects, or differences in urine production, but it does not by itself establish a specific disorder.

Short name

24-Hour Urine GABA/Creatinine Ratio

Frequently asked questions

Why is creatinine included in the result?
Creatinine is used to help account for variations in urine concentration. Comparing GABA with creatinine can make the result more useful across patients or urine samples.
How should I collect a 24-hour urine sample?
Collect every drop of urine during the specified 24-hour period into the provided container. Record the start and end times and return the container according to the laboratory's instructions.
Does fasting or exercise affect this test?
Special preparation is not commonly required, but your clinician or laboratory may provide specific instructions. Tell the healthcare team about medications, supplements, unusual diet, or major changes in activity.
  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