How much hair do they take for a drug test
How Much Hair Do They Take for a Drug Test and Why It Matters
How much hair do they take for a drug test depends on the testing requirements, but typically about 1.5 inches of hair length and a small bundle roughly the size of a pencil eraser is collected. This sample size allows labs to detect drug use over a 90-day period reliably. Call (877) 731-6362 for more details or to schedule a collection.
How much hair do they take for a drug test?
The typical amount of hair taken for a drug test is approximately 1.5 inches in length and about 100-120 strands, which is roughly the size of a pencil eraser or a small coin. This amount provides enough material for laboratories to conduct a thorough analysis of drug metabolites over an extended detection window.
Why is the length of hair important in drug testing?
The length of hair collected, usually 1.5 inches, corresponds to about a 90-day detection window. Hair grows approximately half an inch per month, so this length captures drug use over the past three months. Shorter samples provide less historical data, while longer samples may be more difficult to collect and process.
How is the hair sample collected for drug testing?
A trained collector cuts hair close to the scalp, usually from the crown or back of the head, to ensure the sample reflects recent growth. The hair is placed in a tamper-evident envelope and sent to one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox.
What happens to the hair sample after collection?
Once collected, the hair sample undergoes initial screening for drug metabolites. Any non-negative results are reviewed by a certified Medical Review Officer (MRO) to confirm findings and rule out potential false positives. This review is standard for all AMH Nationwide drug test processing.
Need to Know How Much Hair Is Taken for Your Drug Test?
Call (877) 731-6362 to speak with a representative who can guide you through the hair drug testing process and help you find a nearby collection site.
Are hair drug tests regulated differently for DOT and non-DOT testing?
DOT-regulated safety-sensitive testing requires urine testing under federally certified protocols (49 CFR Part 40). Hair testing is used primarily for non-DOT roles because it provides a longer detection window. AMH Nationwide follows all regulatory guidelines and directs collection accordingly.
Does the amount of hair taken affect the cost of the drug test?
The amount of hair taken generally does not affect the cost directly. Pricing varies based on the drug panel selected and the detection window required. For a precise quote, contact AMH Nationwide directly. Collection is arranged through a local site with no online ordering.
Common Questions
Yes. Hair drug tests typically analyze 1.5 inches of hair, representing about 90 days of drug use history.
Generally, yes. About 100-120 strands or a pencil eraser-sized sample is standard, but it may vary slightly depending on hair thickness.
Body hair can be used if scalp hair is unavailable, but detection windows and test results may vary due to different growth rates.
If hair is too short, a shorter detection window is tested, or alternative tests like urine may be recommended.
Hair tests detect metabolites incorporated into hair shafts; passive exposure generally does not produce positive results confirmed by an MRO.
All non-negative hair drug test results are reviewed by a certified Medical Review Officer to ensure accuracy and reliability.
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.