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Phenylglyoxylic Acid in Urine (via Mass Spectrometry)

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

This test measures the presence of phenylglyoxylic acid in your urine, often used to assess metabolic or genetic conditions affecting phenylalanine metabolism.

Quick summary

["Detects abnormal phenylalanine breakdown that may signal metabolic disorders."]

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

Key facts at a glance

LOINC
111389-3
Short code
3Me4OH-phenylglycol Msmt Ur
Synonyms
3Me4OH-phenylglycol Msmt Ur
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 like developmental delays, behavioral issues, or if you have a family history of metabolic disorders such as phenylketonuria (PKU). It can also be part of routine screening for certain genetic conditions.

What to Expect Before the Test

No special preparation is needed. You may be asked to collect a urine sample in the morning or at a specified time. Follow your provider’s instructions carefully to ensure accurate results.

How the Test Works

A small sample of your urine is sent to a lab where it is analyzed using mass spectrometry. This method detects phenylglyoxylic acid by measuring its unique molecular structure.

What the Results Mean

Results may indicate an abnormal metabolic pathway. Elevated levels could suggest conditions affecting phenylalanine metabolism, but interpretation depends on clinical context and other test results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: This test is primarily used to diagnose or monitor conditions related to phenylalanine metabolism disorders. Elevated levels may point to conditions like phenylketonuria or other inborn errors of metabolism that require early intervention to prevent long-term health issues.

Short name

Phenylglyoxylic Acid Urine Test

Frequently asked questions

What causes abnormal phenylglyoxylic acid levels?
Abnormal levels are often linked to genetic mutations affecting enzymes involved in phenylalanine metabolism. Conditions like phenylketonuria (PKU) or other metabolic disorders can cause these elevations.
Can diet affect this test?
Yes, diet may influence phenylalanine levels. If you are being monitored for a metabolic disorder, your provider will likely give specific dietary guidelines to help manage your condition.
How often will I need this test?
Frequency depends on your medical condition and treatment plan. Your healthcare provider will determine how often this test should be repeated, typically based on your symptoms, lab results, and overall health status.
  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