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JWH-018 Carboxy Metabolite/Creatinine Ratio, Urine

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

A urine test that detects exposure to the synthetic cannabinoid JWH-018 using its carboxy metabolite, with creatinine used to account for urine concentration.

Quick summary

["A detected JWH-018 carboxy metabolite can indicate recent exposure to this synthetic cannabinoid."]

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

Key facts at a glance

LOINC
72809-7
Short code
JWH-018 carboxylated/Creat Ur
Synonyms
JWH-018 carboxylated/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 test looks for a carboxy metabolite of JWH-018, a synthetic cannabinoid sometimes called “Spice,” in urine. The result may be compared with urine creatinine to help account for differences in urine concentration.

Why might I need this test?

It may be ordered when someone is being evaluated for possible exposure to synthetic cannabinoids, particularly in workplace, school, legal, or substance-use monitoring programs.

How is the test performed?

A urine specimen is collected and analyzed by the laboratory for JWH-018 metabolites. If the result is reported as a creatinine ratio, the metabolite measurement is adjusted using the amount of creatinine in the same urine sample.

How do I prepare for the test?

No fasting is usually required. Collect urine in the container and at the time specified by the testing program, and tell the laboratory or clinician about any medications or supplements you have recently used.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Detecting the JWH-018 carboxy metabolite suggests that the person was exposed to JWH-018 or a related product. The result does not by itself show when exposure occurred, how much was taken, or whether the person was impaired. A negative result means the metabolite was not detected and does not completely exclude exposure.

Short name

JWH-018 carboxy metabolite, urine

Frequently asked questions

What does a positive result mean?
It indicates that laboratory testing found a metabolite associated with JWH-018 exposure. It does not determine impairment, the amount used, or the exact time of exposure.
Why is creatinine included?
Creatinine is used to help normalize the metabolite result for how concentrated or dilute the urine sample is. This can make results from different urine samples easier to compare.
Can this test determine when someone used the substance?
No. The test identifies evidence of exposure but cannot precisely establish the dose or time of use. Results should be interpreted with the timing of the urine collection and the clinical context.
  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