How long does thc stay in your hair follicles
How Long Does THC Stay in Your Hair Follicles for Reliable Drug Testing
How long does THC stay in your hair follicles depends on usage and hair growth, typically detectable up to 90 days. Hair follicle testing provides a long-term window for THC detection. AMH Nationwide processes tests through five national labs with certified Medical Review Officers. Call (877) 731-6362.
How long does THC stay in hair follicles after use?
THC can be detected in hair follicles for up to 90 days after use. This detection window reflects the time it takes for hair containing THC metabolites to grow out from the scalp. Hair drug tests typically analyze 1.5 inches of hair closest to the scalp, representing approximately three months of growth.
How does hair follicle testing detect THC?
Hair follicle testing detects THC by analyzing hair samples for metabolites deposited in the hair shaft during growth. When THC is consumed, it is metabolized and enters the bloodstream, where it can be incorporated into hair follicles. The collected hair sample is sent to one of AMH’s five national lab networks for analysis.
Is hair follicle testing suitable for all employment drug screenings?
Hair follicle testing is commonly used for non-DOT safety-sensitive positions due to its long detection window. DOT-regulated testing requires urine testing under federally certified protocols. Hair tests are preferred when historical drug use information is needed rather than recent use.
Does frequency of marijuana use affect how long THC stays in hair follicles?
Yes, frequency and amount of marijuana use influence THC levels in hair follicles. Chronic or heavy users typically have higher concentrations and longer detection times. Occasional or one-time use may result in lower metabolite levels, but THC can still be detected within the 90-day window.
Need Accurate THC Hair Follicle Testing?
Contact AMH Nationwide to schedule hair follicle drug testing through authorized collection sites. Call (877) 731-6362 for assistance and pricing details.
Can passive marijuana exposure cause a positive hair follicle test?
Passive exposure to marijuana smoke is unlikely to cause a positive hair follicle test because the test detects metabolites incorporated through bloodstream, not external contamination. Laboratories follow strict protocols to differentiate between actual use and environmental exposure.
How reliable are hair follicle tests for detecting THC?
Hair follicle tests are highly reliable when processed through accredited labs and reviewed by certified Medical Review Officers. AMH Nationwide routes samples through five national labs with SAMHSA-aligned, CAP, and CLIA certifications, ensuring accuracy and compliance.
Common Questions
THC metabolites typically appear in hair follicles about 5 to 10 days after use, as hair must grow out from the scalp for detection. Testing usually analyzes hair closest to the scalp to identify recent drug use within approximately three months.
Hair follicle tests are sensitive and can detect low levels of THC metabolites, but thresholds are set to minimize false positives. Confirmatory testing and Medical Review Officer evaluations ensure accurate interpretation.
Hair color and type may have minor effects on metabolite incorporation, but accredited labs use standardized methods to ensure consistent results across diverse hair samples.
A small sample of hair, typically 1.5 inches long and about the width of a pencil, is cut close to the scalp at authorized collection sites. The sample is sealed and sent to certified labs for analysis.
All non-negative hair follicle test results undergo review by a certified Medical Review Officer who evaluates medical explanations or prescriptions before confirming a positive report.
Hair follicle testing is not effective for detecting marijuana use within the past few days because hair must grow out to incorporate metabolites. Urine or saliva testing is more appropriate for recent use detection.
Ready to get started?
AMH Nationwide provides the lab order and arranges collection nationwide. Every non-negative result reviewed by a certified Medical Review Officer. Call (877) 731-6362 or contact us.