Gamma-Aminobutyric Acid/Creatinine Ratio, 24-Hour Urine
Measures urinary gamma-aminobutyric acid relative to creatinine in a 24-hour urine collection to help assess GABA metabolism.
["This specialized urine test measures how much GABA is excreted relative to creatinine, with interpretation based on the complete collection and your clinical situation."]
Key facts at a glance
- LOINC
- 25915-0
- Short code
- GABA/Creat 24h Ur-sRto
- Synonyms
- GABA/Creat 24h Ur-sRto
- 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 that acts as an inhibitory neurotransmitter in the nervous system. This test measures GABA in relation to creatinine in urine collected for 24 hours, which helps account for differences in urine concentration.
Why might I need this test?
A clinician may order this test as part of a specialized evaluation of suspected abnormalities in neurotransmitter metabolism. It may also be used to follow selected patients when the healthcare team has a specific clinical reason to monitor GABA excretion.
How is the test performed?
You collect all urine produced during a full 24-hour period using the container and instructions provided by the laboratory. The laboratory measures GABA and creatinine and reports the amount of GABA relative to the amount of creatinine.
How do I prepare for the test?
Follow the laboratory's collection instructions carefully and record the start and finish times. Avoid missing urine or accidentally including urine from before or after the collection period, and return the container as directed. Do not change your diet or medications unless your clinician specifically tells you to do so.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated or reduced GABA-to-creatinine ratio may reflect altered GABA metabolism or excretion, but results can also be affected by incomplete collection, hydration, medications, and other factors. The result should be interpreted by the ordering clinician alongside symptoms, medication use, and other laboratory findings. This test alone does not establish a diagnosis.
Short name
24-Hour Urine GABA/Creatinine Ratio
Frequently asked questions
Why is creatinine included in this test?
Does a 24-hour urine test require fasting?
What happens if part of the urine collection is missed?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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