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Methionine/Creatinine Ratio, Urine

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

A urine test that measures methionine relative to creatinine, helping account for variations in urine concentration.

Quick summary

["This ratio helps evaluate how much methionine is being lost in urine relative to creatinine."]

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

Key facts at a glance

LOINC
30063-2
Short code
Methionine/Creat Ur-Rto
Synonyms
Methionine/Creat 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?

This test measures the amount of methionine in urine compared with the amount of creatinine. Creatinine is used as a reference to help account for how concentrated or dilute the urine sample is.

Why might I need this test?

It may be used to evaluate methionine excretion, particularly during follow-up for a suspected inherited metabolic condition or when monitoring dietary methionine or supplementation. It is interpreted together with the person's age, diet, medications, and other laboratory results.

How is the test performed?

A urine sample is collected as directed by the laboratory. The laboratory measures methionine and creatinine and then calculates the methionine-to-creatinine ratio.

How do I prepare for the test?

Follow the collection instructions provided by your healthcare professional, including any specified collection time or container. Your clinician may advise you to maintain your usual diet and avoid changing supplements unless instructed otherwise.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A higher ratio may reflect increased methionine excretion, a high-protein diet, recent supplementation, or differences in kidney handling. An abnormal result does not by itself establish a metabolic disorder and may need confirmation with repeat testing and additional blood or urine studies.

Short name

Urine methionine/creatinine ratio

Frequently asked questions

Is this the same as a blood methionine test?
No. This test measures methionine and creatinine in urine, while a blood methionine test measures methionine concentration in blood.
Why is creatinine included in the result?
Urine can vary greatly in concentration. Comparing methionine with creatinine helps reduce the effect of urine dilution or concentration on the result.
Does an abnormal ratio diagnose a metabolic disorder?
No. An abnormal result can have several causes and should be interpreted by a clinician, often with repeat testing and other laboratory results.
  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