How much hair is needed for a drug test
How Much Hair Is Needed for a Drug Test to Ensure Accurate Results
How much hair is needed for a drug test depends on the testing method; typically, a 1.5-inch hair sample about the diameter of a pencil is required for a hair follicle test. This provides a detection window of up to 90 days. AMH Nationwide routes collections through five national labs with certified Medical Review Officer oversight. Call (877) 731-6362.
How much hair is needed for a hair follicle drug test?
A standard hair follicle drug test requires approximately 1.5 inches of hair length, taken from close to the scalp, with a diameter roughly equal to a pencil’s width. This amount is generally sufficient to provide a 90-day drug use history. The hair sample is cut from the crown or back of the head where growth is most consistent.
How much hair do they take for a drug test?
During collection, a small cluster of hair strands is cut close to the scalp using clean scissors. The sample size is about 100 to 120 strands, ensuring enough material for accurate testing across the required detection window. If the individual has very short hair, body hair may be used as an alternative, but it may affect detection time frames.
Should I cut my hair before a hair drug test?
Cutting your hair before a hair follicle drug test is generally not advisable. The lab needs sufficient length—around 1.5 inches—to analyze drug metabolites incorporated into the hair shaft over time. Cutting hair short may reduce the detection window or lead to insufficient sample size, which might delay results or require retesting.
Why is a 1.5-inch hair sample required for a drug test?
A 1.5-inch hair sample corresponds to approximately 90 days of hair growth, as hair grows about half an inch per month. This length allows testing laboratories to detect drug metabolites deposited in the hair shaft during this period. Shorter samples provide a shorter detection window, limiting the test’s ability to identify past drug use.
Ready to Schedule Your Hair Follicle Drug Test?
Call (877) 731-6362 to speak with an AMH Nationwide representative. We will guide you through the testing process and direct you to a collection site near you.
Which labs process hair follicle drug tests for AMH Nationwide?
AMH Nationwide directs hair follicle drug test collections to five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, and ExperTox. Each lab follows strict chain-of-custody and testing protocols. Every non-negative result is reviewed by a certified Medical Review Officer to ensure accuracy and compliance.
How do I arrange a hair follicle drug test with AMH Nationwide?
AMH Nationwide provides the lab order and directs you to a nearby collection site. There is no online ordering available. To arrange a hair follicle drug test or for questions about sample requirements and detection windows, call (877) 731-6362. Pricing varies based on the testing panel and detection window.
Common Questions
Yes, body hair can be collected if head hair is insufficient. However, body hair has a different growth rate and detection window, which may affect test results and interpretation.
Results typically take 3 to 5 business days after the lab receives the sample, depending on the lab network and testing panel selected.
Hair treatments like bleaching or dyeing may reduce drug metabolite concentrations but do not guarantee evasion. Labs have methods to detect sample tampering or adulteration.
Hair testing reflects drug use over the past 90 days but does not detect very recent use within the last 7 days due to the time required for drug metabolites to incorporate into the hair shaft.
No, DOT-regulated safety-sensitive testing requires urine collection under the federally certified protocol 49 CFR Part 40. Hair testing is generally used for non-DOT roles.
Refusing a drug test may have legal or employment consequences depending on the situation. Always discuss concerns with the requesting party or legal advisor before declining.
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.