How far back does a hair follicle go back
How Far Back Does a Hair Follicle Go Back for Drug Detection Benefits
How far back does a hair follicle go back is a common question regarding hair drug testing. Typically, hair follicle tests detect drug use up to 90 days prior by analyzing a 1.5-inch hair sample. This method provides a longer detection window than urine or saliva tests. Call (877) 731-6362 to schedule your test or learn more.
How far back does a hair follicle go back in drug testing?
A hair follicle drug test can detect drug use from approximately 7 days after use up to 90 days prior. The standard sample length is 1.5 inches of hair, which correlates roughly to a 3-month growth period. This makes hair testing useful for identifying past drug use over a longer period than urine or saliva tests.
How is the hair follicle sample collected and processed?
Hair samples are collected by cutting a small amount of hair close to the scalp, usually from the crown area. The sample is then sent to one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox. Each sample undergoes screening and confirmation testing, with all non-negative results reviewed by a certified Medical Review Officer.
What substances can be detected in hair follicle testing?
Hair follicle testing can detect a variety of substances including marijuana, cocaine, amphetamines, opioids, PCP, and others. The detection window and sensitivity depend on the drug and hair growth rate. Hair testing is especially valuable for its ability to detect chronic or repeated drug use over weeks to months.
Are there limitations to how far back hair follicle testing can detect drugs?
Yes. Hair follicle tests generally do not detect drug use from the past week because hair must grow out from the scalp to contain drug metabolites. Also, hair length limits the detection window to about 90 days. External contamination and hair treatments can affect results, but certified labs follow strict protocols to ensure accuracy.
Ready to test with confidence?
Call (877) 731-6362 to arrange hair follicle drug testing through AMH Nationwide. Our labs follow strict protocols with certified Medical Review Officer review.
Who typically orders hair follicle drug testing and why?
Employers, courts, probation agencies, and individuals order hair follicle drug tests to verify drug use history over an extended period. Hair testing is preferred when a longer detection window is required or when urine testing is not suitable. DOT-regulated testing does not use hair testing, requiring federally certified urine protocols instead.
How can I arrange hair follicle drug testing with AMH Nationwide?
AMH Nationwide provides lab orders and directs you to one of over 20,000 collection sites nationwide. There is no online ordering; all requests must be made by phone. Call (877) 731-6362 to discuss your testing needs, get a price quote, and schedule your collection appointment.
Common Questions
Hair follicle testing typically detects drug use starting about 7 days after use, as it takes time for drug metabolites to be incorporated into the growing hair shaft.
Hair testing is more effective at detecting repeated or chronic drug use, but a single use may be detected depending on timing and drug concentration.
Hair color and type can influence drug incorporation slightly, but certified labs account for these variables to maintain test accuracy.
Hair treatments may reduce detectable drug levels but do not guarantee a negative result. Labs use methods to minimize interference from cosmetic treatments.
No. DOT-regulated safety-sensitive testing requires federally certified urine testing protocols under 49 CFR Part 40. Hair testing is used for non-DOT testing.
Results typically take several days to a week, depending on the lab and confirmation testing requirements.
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.