What can cause a false positive hair follicle test
What Can Cause a False Positive Hair Follicle Test and How to Understand It
What can cause a false positive hair follicle test? Common causes include environmental contamination, certain medications, and hair treatments. Hair follicle testing is highly accurate with strict lab protocols, including review by a certified Medical Review Officer. For questions or to schedule testing, call (877) 731-6362.
What is a hair follicle drug test and how accurate is it?
A hair follicle drug test detects drug metabolites embedded in the hair shaft, reflecting drug use over approximately 90 days. This test is highly accurate due to its long detection window and the ability to distinguish drug use from passive exposure.
AMH Nationwide routes collections through five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, and ExperTox. All samples are reviewed by certified Medical Review Officers to ensure accuracy and reliability.
What can cause a false positive hair follicle test?
False positives in hair follicle tests are rare but can occur. Common causes include environmental contamination, certain medications, and cosmetic hair treatments.
For example, exposure to secondhand smoke or handling drugs may deposit trace amounts on hair surfaces, but labs use washing procedures to reduce this risk.
Some medications and drug metabolites may cross-react in immunoassays, but confirmatory testing by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) minimizes false positives.
Can environmental exposure cause a false positive hair follicle test?
Environmental exposure to drugs or drug smoke can deposit residues on hair surfaces, but standard lab washing protocols remove external contamination before analysis.
Passive exposure alone is unlikely to cause a positive result because the test detects metabolites incorporated inside the hair shaft, not just surface contamination.
However, extreme or repeated exposure in certain environments could potentially affect results, which is why Medical Review Officers evaluate all non-negative findings.
Do medications cause false positive hair follicle tests?
Certain medications can cause false positives in initial screening tests due to chemical similarities with drugs of abuse.
Confirmatory testing performed by the labs routed through AMH Nationwide uses highly specific methods to differentiate medications from illicit substances.
Individuals should disclose prescribed medications to the Medical Review Officer if a non-negative result occurs to ensure accurate interpretation.
Need Reliable Hair Follicle Testing?
Contact AMH Nationwide to schedule testing or discuss concerns about false positives. Call (877) 731-6362 for assistance.
Can hair treatments affect hair follicle test results?
Hair treatments such as bleaching, dyeing, perming, or excessive shampooing may reduce drug metabolite concentrations in hair samples.
These treatments do not cause false positives but may cause false negatives by degrading the sample or masking drug presence.
Laboratories consider hair condition during analysis and may request additional testing or alternative specimen types if needed.
How do labs prevent false positives in hair follicle testing?
Labs follow strict protocols including washing hair samples to remove external contaminants.
Confirmatory testing using GC-MS or LC-MS/MS is standard to verify initial positive screens.
Certified Medical Review Officers review all non-negative results to differentiate true positives from possible false positives based on medical history, medications, and other factors.
AMH Nationwide directs the requester to collection sites; there is no online ordering to ensure proper chain of custody and protocol compliance.
Common Questions
Certain medications, like some cold remedies or antidepressants, may cause false positives in initial screens, but confirmatory tests differentiate these from illicit drugs.
Hair dye does not cause a positive result but may reduce detectable drug metabolite levels, potentially leading to false negatives rather than false positives.
While external contamination is possible, lab washing procedures and metabolite detection inside the hair shaft minimize false positives from environmental exposure.
Hair follicle tests can detect drug use for up to 90 days because metabolites are incorporated into hair as it grows.
A certified Medical Review Officer reviews all non-negative results to confirm accuracy and consider medical explanations before reporting results.
Yes, bleaching and other chemical treatments can degrade drug metabolites in hair, possibly causing false negatives but not false positives.
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.