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Hair Drug Testing

Hair testing is a process in which hair specimens are analyzed for the use of illicit drugs. iMED Laboratories uses detection levels and confirmation methods that follow government recommendations.

While some laboratories may take over a week to report a confirmed positive, Omega consistently achieves the same results in three business days. Omega’s turnaround time is based on laboratory-proven proprietary testing methods, which are part of the intellectual property that is unique to Omega. This intellectual property includes a proprietary specimen wash method, which has been approved by multiple accrediting agencies as an effective means for removing external contamination. Unlike other longer washes, Omega’s proprietary wash method does not inadvertently remove metabolites, which can lead to false negatives. iMED Laboratories in conjunction with Omega laboratories is one of only three hair testing laboratories in the world to have obtained FDA 510(k) clearances

When compared to other forms of testing, hair samples can detect a much longer period of drug use. For example, urinalysis can only detect most drugs within 2-3 days of use. After this period, a donor will be free of the drug, test negative and slip through the screening process. By comparison, the industry standard is to test 1.5 inches of head hair for approximately 90 days of history. This is important in pre-employment testing where most candidates are aware that a drug test might be required and can otherwise abstain accordingly.

Process Overview

The four main steps involved in the laboratory processing of a drug test result are Accessioning, Screening, Extraction, and Confirmation.


Accessioning involves the initial processing of a sample into a laboratory’s system. This includes verifying that the sample was sealed and shipped properly, assigning a random LAN (Laboratory Accessioning Number), and completing any additional data entry not provided by an electronic chain of custody system.


Screening involves an initial quick check for drugs of abuse. While Screening is a cost-effective way to rule out drug usage on the majority of samples, a positive screen needs to be confirmed to be admissible in court. Any samples that are presumptively positive in Screening do require a secondary confirmation.


If a sample is presumptively positive in the Screening stage, more hair is pulled from the initial specimen and prepared for Extraction. In this stage, drugs are extracted from hair at a much lower concentration than in other methodologies (ex. urine or oral fluid), which is why hair drug screening is the most difficult methodology to perform.


Confirmation of any positive screening result is conducted via GC/MS, GC/MS/MS or LC/MS/MS. All presumptive positive samples are washed prior to confirmation as needed. The entire laboratory process from Accessioning to Confirmation is reviewed under both the CAP (College of American Pathologists) Hair designation and the accreditation to ISO / IEC 17025 standards.