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Homocysteine (Free) in Urine

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

This test measures the amount of free homocysteine, a form of the amino acid homocysteine, found in your urine. It helps assess how well your body is processing this compound, which can be linked to certain health risks.

Quick summary

["Free homocysteine in urine may indicate metabolic or kidney-related issues that need further evaluation."]

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

Key facts at a glance

LOINC
33936-6
Short code
Homocystine.free Ur-sCnc
Synonyms
Homocystine.free Ur-sCnc
Category
chemistry
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 Is This Test Done?

Your healthcare provider may order this test if you have symptoms or risk factors for conditions like kidney disease, metabolic disorders, or genetic conditions affecting homocysteine metabolism. It can also be part of a broader evaluation for unexplained health concerns.

What Does the Result Mean?

Urine free homocysteine levels alone are not typically interpreted in isolation. Results are usually reviewed alongside clinical findings, other tests, and medical history to determine if further action is needed. Elevated levels may suggest potential kidney function issues or metabolic imbalances.

How Is the Test Performed?

You will likely provide a urine sample, usually collected over a specified period (such as 24 hours), depending on the protocol. The sample is sent to a lab where it is analyzed to measure free homocysteine concentration.

What Are Common Causes of Abnormal Results?

High levels of free homocysteine in urine may be associated with kidney problems, certain genetic conditions, or metabolic disorders. Low levels are less commonly evaluated but could be part of a broader metabolic assessment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Homocysteine Metabolism and Health Risks

Short name

Urine Free Homocysteine

Frequently asked questions

What Factors Might Affect My Test Results?
Several factors can influence urine homocysteine levels, including diet (especially folate, vitamin B6, and B12 intake), kidney function, hydration status, and certain medications. Avoiding certain foods or supplements for a few days before testing may help ensure accurate results.
Do I Need to Prepare for This Test?
Preparation may vary, but generally, you should avoid excessive alcohol, certain medications, or specific dietary restrictions as directed by your healthcare provider. Follow any instructions provided with your test kit or by your lab.
Is This Test Painful or Invasive?
No, this test involves providing a urine sample, which is typically non-invasive and painless. You may need to collect urine over a set period, such as 24 hours, depending on the test protocol.
  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