4-Hydroxyphenylglycoluric acid (4-OHPG) urine
This test measures the presence of 4-hydroxyphenylglycoluric acid, a breakdown product of certain neurotransmitters, in your urine. It may be used to help diagnose or monitor conditions affecting metabolism or neurotransmitter function.
["This test helps assess metabolic or neurotransmitter-related health concerns through urine analysis."]
Key facts at a glance
- LOINC
- 43634-5
- Short code
- 3Me4OH-phenylglycol Ur Ql
- Synonyms
- 3Me4OH-phenylglycol Ur Ql
- Category
- glucose
- 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
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms or risk factors for conditions like phenylketonuria (a genetic disorder affecting metabolism) or other metabolic or neurological issues. It may also be part of a broader evaluation for unexplained neurological symptoms or genetic testing.
How the Test Works
A small urine sample is collected and analyzed to detect the chemical compound 4-hydroxyphenylglycoluric acid. The test typically involves specialized laboratory techniques to identify and quantify this substance in your urine.
Sample Collection
You will likely be instructed to collect a 24-hour urine sample, starting from the first morning void until the next morning’s first void. This ensures a representative measure of your body’s natural production of the compound over a full day.
What to Expect Before the Test
No special preparation is usually required, but you may need to avoid certain medications or foods that could interfere with the test results. Always follow your healthcare provider’s specific instructions.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated levels of 4-hydroxyphenylglycoluric acid in urine may indicate metabolic disorders such as phenylketonuria or other conditions affecting neurotransmitter metabolism. It can also be part of diagnostic workup for neurological symptoms or genetic testing for inherited metabolic diseases.
Short name
4-OHPG Urine
Frequently asked questions
What does a positive result mean?
How long will it take to get results?
Can I drink alcohol before this test?
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