How long back does hair drug test go
How Long Back Does Hair Drug Test Go for Reliable Drug Detection
How long back does hair drug test go? Hair follicle drug tests typically detect drug use within the past 90 days, providing a longer detection window than urine or saliva tests. This makes them valuable for employers, courts, and probation agencies. AMH Nationwide works with five national labs for accurate results. Call (877) 731-6362.
How long back does a hair follicle drug test go?
A hair follicle drug test can detect drug use for up to 90 days prior to the test date. This extended detection window is due to the way drugs are deposited in the hair shaft as it grows. Typically, a 1.5-inch hair sample is collected to capture approximately three months of drug history.
This makes hair follicle tests useful for identifying patterns of drug use over time, unlike urine tests which detect recent use within days.
How does the hair drug testing process work at AMH Nationwide?
AMH Nationwide facilitates hair drug tests through five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, and ExperTox. We provide the lab order and direct the requester to an approved collection site.
During collection, a small sample of hair is taken, usually from the crown of the head. The sample is sent to the lab where it undergoes testing for specific drug metabolites. All non-negative results are reviewed by a certified Medical Review Officer as part of standard processing.
Which drugs can be detected by a hair follicle drug test?
Hair follicle drug tests can detect a range of commonly abused substances including:
The detection includes but is not limited to:
– Amphetamines
– Cocaine
– Marijuana (THC)
– Opiates (heroin, morphine, codeine)
– Phencyclidine (PCP)
– Benzodiazepines and Barbiturates (depending on the test panel)
How does hair follicle testing compare to other drug tests?
Hair follicle testing offers a significantly longer detection window compared to urine, saliva, or blood tests. The table below summarizes typical detection periods:
| Test Type | Detection Window |
|---|---|
| Urine Drug Test | 1-7 days |
| Saliva Drug Test | 1-3 days |
| Blood Drug Test | Up to 24 hours |
| Hair Follicle Drug Test | Up to 90 days |
Arrange Hair Follicle Drug Testing with AMH Nationwide
To schedule a hair follicle drug test that covers up to 90 days of drug history, call (877) 731-6362. We work with five national labs to ensure accurate results and Medical Review Officer oversight.
Are there limitations to how long back a hair follicle drug test can detect drugs?
Yes, hair follicle drug tests typically do not detect drug use beyond approximately 90 days due to the length of hair sampled. Very recent drug use within the past 7 days may also not be detected because it takes time for drugs to incorporate into the hair shaft.
Additionally, hair treatments or very short hair length might affect sample collection but do not invalidate the test if the lab can obtain sufficient hair.
Who orders hair follicle drug tests and why?
Employers, courts, probation and parole agencies often order hair follicle drug tests when they need to assess drug use over an extended period. These tests provide a reliable history of drug consumption for up to three months.
Individuals may also request hair follicle testing for personal reasons or legal requirements. AMH Nationwide does not provide online ordering; call (877) 731-6362 to arrange testing.
Common Questions
Hair follicle testing generally detects drug use about 5 to 7 days after consumption, as it takes time for drugs to incorporate into the hair shaft.
Yes, hair follicle tests can detect single instances of drug use within the past 90 days, but detection depends on the timing and amount of drug consumed.
Some studies suggest that hair color and texture might influence drug absorption, but labs account for these factors. Testing is considered reliable across hair types.
Hair treatments may reduce drug concentrations but do not guarantee a negative result if drug use occurred. Labs evaluate sample integrity during analysis.
No, DOT-regulated safety-sensitive testing requires federally certified urine testing under 49 CFR Part 40. Hair testing is for non-DOT roles.
AMH Nationwide provides lab orders and directs you to a collection site. Call (877) 731-6362 to start the process; online ordering is not available.
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.