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JWH-018 Pentanoic Acid Metabolite/Creatinine Ratio, Urine

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

A urine test that measures a breakdown product of the synthetic cannabinoid JWH-018 and adjusts for urine concentration.

Quick summary

["This test can help identify recent exposure to the synthetic cannabinoid JWH-018."]

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

Key facts at a glance

LOINC
72781-8
Short code
JWH-018 pentanol/Creat Ur
Synonyms
JWH-018 pentanol/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 measures a JWH-018 metabolite in urine. The result is compared with the urine creatinine level to account for differences in urine concentration.

Why might I need this test?

It may be ordered when exposure to JWH-018, a synthetic cannabinoid sometimes called “Spice,” is suspected. It is generally used as part of drug testing rather than as a routine health screening test.

How is the test performed?

A urine sample is analyzed in the laboratory to detect the JWH-018 metabolite and measure creatinine. The laboratory reports the metabolite-to-creatinine ratio, which helps reduce the effect of changes in urine concentration.

How do I prepare for the test?

Follow the instructions provided by the ordering clinician or testing laboratory. The test may be performed on a collected urine sample, and the laboratory may use a screening test followed by a confirmatory method.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A detectable result can indicate exposure to JWH-018 or a related substance that produces the same metabolite. Urine testing generally reflects exposure over a recent period, but it cannot by itself show when exposure occurred, how much was taken, or whether impairment is present.

Short name

Urine JWH-018 metabolite-to-creatinine ratio

Frequently asked questions

What does a positive JWH-018 urine test mean?
It indicates that the JWH-018 metabolite was detected and is consistent with recent exposure. Interpretation should consider the test method, the collection time, and the individual’s circumstances.
Is this the same as a general drug screen?
Not necessarily. Some routine drug screens do not include synthetic cannabinoids, so this specific test may need to be ordered separately.
Why is the result divided by creatinine?
Creatinine is used as a marker of urine concentration. Dividing by it helps reduce the effect of very dilute or concentrated urine on the reported result.
  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