With over three decades of experience, Dr. LeBeau specializes in a variety of forensic toxicology topics, including drug-facilitated crimes, poisonings, and postmortem investigations.
Hair Testing for Drugs
Testing hair allows for identification of drugs that a person was exposed to. The technique is useful when longer detection windows are needed, particularly compared to specimens like urine or blood.
What is Involved in Testing
Hair for Drugs?
Hair drug testing involves analyzing a small sample of hair to identify the presence of drugs or their metabolites. The process begins with collection of a hair sample, typically from the scalp, by a trained collector. The sample usually consists of a bundle of hair (about the thickness of a pencil) that is cut close to the scalp and sent to a laboratory for analysis.
Once at the laboratory, the hair sample is washed and then cut into smaller segments. Drugs and their metabolites are extracted from the hair sample by more extensive washing with chemical solvents that remove the analytes trapped within the hair shaft. The extracted substances are then analyzed using highly sensitive instruments, such as gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS). These methods allow for the identification of a wide range of drugs, including marijuana, cocaine, opioids, amphetamines, and more. The analytical results are reviewed and reported as either positive or negative for specific drugs or their metabolites, along with the concentration levels detected.
What are the Advantages of Testing Hair for Drugs?
Testing hair for drugs offers several advantages compared to the testing of other specimens:
- Drugs and metabolites will remain in hair for a much longer period compared to urine or blood.
- Unlike urine tests, which can be manipulated, it is challenging to cheat with a hair test. The drugs become trapped inside the hair shaft as it grows, so it is difficult for individuals to tamper with the results.
- Hair testing can identify a wide range of drugs, providing a comprehensive overview of an individual’s drug use history.
The collection of a hair sample is non-invasive and painless, making it a more comfortable option for the individuals undergoing testing.
What are the Limitations of Testing Hair for Drugs?
Hair drug testing is not perfect, so it is important to understand its limitations:
- There are only a few laboratories in the United States that offer testing of hair for drugs.
- Hair testing can be very expensive compared to the cost of testing the more traditional specimens.
- Results from hair testing cannot determine the exact timing of drug use or exposure. Instead, the results of hair tests can only confirm the presence of drugs during the period of growth represented by the tested hair sample.
- External contamination from environmental exposure to drugs can potentially lead to false-positive results. However, laboratories employ strict protocols to minimize this risk.
- Hair testing is not suitable for detecting recent drug use, as it takes several days for drugs to become incorporated into the hair at the root and to grow above the scalp.
Dr. LeBeau’s Experience in Testing Hair for Drugs
Dr. LeBeau has over 30 years of experience testing hair for drugs and interpreting the results from this testing. Of note are his publications and presentations focused on improving collection, testing, and interpretation of results from this challenging matrix, Contact LeBeau Forensic Toxicology Consulting and ask for a copy of his CV to learn more.
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