Skip to content

Ketamine/Creatinine Ratio, Urine

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

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

Quick summary

["This test can help identify recent ketamine exposure, but the result cannot determine the exact dose or time of use."]

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

Key facts at a glance

LOINC
72801-4
Short code
Ketamine/Creat Ur
Synonyms
Ketamine/Creat Ur
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 urine test measures the amount of ketamine in the urine relative to creatinine, a waste product normally found in urine. The ratio helps reduce the effect of changes in urine concentration.

Why might I need this test?

It may be used for substance-use monitoring, drug screening, or investigating suspected ketamine exposure. It may also be ordered as part of certain workplace, medical, or legal assessments.

How is the test performed?

A urine sample is collected and analyzed in the laboratory for ketamine and creatinine. The laboratory may report the ketamine-to-creatinine ratio, and a separate qualitative ketamine screen may also be provided.

How do I prepare for the test?

Follow the laboratory's urine-collection instructions, and tell the clinician about prescription medicines, supplements, and over-the-counter products you have used. Unless specifically instructed, do not deliberately drink large amounts of water or take extra fluids before collection.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine ketamine-to-creatinine ratio

Frequently asked questions

Does a positive result mean someone took ketamine?
Usually, yes, but the result should be interpreted with the collection time, medical history, and other test findings. Ketamine exposure may also result from legitimate medical use.
How long can ketamine be detected in urine?
Detection depends on the amount used, frequency of use, urine concentration, and other individual factors. A negative result at one collection time does not rule out use at another time.
Why is the result reported as a ratio to creatinine?
Urine can vary greatly in concentration. Comparing ketamine with creatinine helps account for whether a urine sample is concentrated or diluted.
  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