Toxicology

Marijuana Metabolite (THC)

Normal Range
Negative (<50 ng/mL for screening)
Sample Type
Standard
Fasting
No
Unit
ng/mL

This test measures the primary inactive metabolite of Tetrahydrocannabinol (THC), specifically 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), in the urine. As part of a DOA 5-Panel, it is used to screen for cannabis consumption. Because THC is lipophilic, it is stored in fat cells and released slowly, allowing for a detection window ranging from a few days for occasional users to several weeks for chronic users. It identifies exposure rather than acute impairment.

Check Your Result

Check Your Result

Interactive
ng/mL

Enter your lab result to see where you stand compared to the standard reference range.

Why Context Matters

False positives, though rare with modern immunoassays, can occur due to cross-reactivity with certain non-steroidal anti-inflammatory drugs (NSAIDs) or proton pump inhibitors. Furthermore, 'passive inhalation' is a common legal defense, though it rarely reaches the standard 50 ng/mL cutoff. A second opinion or confirmatory GC/MS (Gas Chromatography-Mass Spectrometry) is essential for legal or employment-terminating results.

Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.

Clinical References

Source-of-truth databases and clinical guidelines for Marijuana Metabolite (THC):

Related Indicators

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Medically Reviewed by Dr. Binoy Babu, MBBS

Board Certified Doctor • 10+ Years Clinical Experience

Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.

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