Understanding hair drug test reports – a comprehensive guide

Hair drug testing – also known as hair strand or hair follicle testing – is an extremely valuable tool for legal professionals, social workers and local authorities working on child welfare and protection cases, and is widely used for determining patterns of drug use.

However, interpreting a hair drug test report requires more than simply reading the results, as there are numerous other factors that must also be considered.

A well-structured, scientifically-backed report should provide full transparency and context, allowing authorities to make informed, timely decisions in the best interests of the children and families involved.

Here, we examine the role of cut-off levels in ensuring reliable results, why expert interpretation is essential, what’s included in a hair drug test report, and the holistic nature of AlphaBiolabs’ drug test reports.

The role of cut-off levels in hair drug testing

While some testing laboratories do not actively employ the use of cut-off levels in their analysis, cut-off levels play a crucial role in ensuring the accuracy and fairness of hair drug testing.

Without cut-off levels, even trace amounts of substances could be reported, potentially resulting from passive exposure to drugs rather than active drug use. One example of such a scenario is the ‘cocaine kiss’.

Cocaine can dissolve in saliva and be absorbed through the soft tissues in the mouth. This means that even a small amount of cocaine has the potential to be transferred to a non-cocaine user, through kissing.

Due to the sensitivity of modern-day drug testing, this can result in the person testing positive for cocaine even if they did not actively use the drug themselves.

At AlphaBiolabs, we follow internationally-recognised cut-off guidelines set by the Society of Hair Testing (SoHT), which bases its recommendations on extensive research across a diverse range of populations.

These scientifically established thresholds are:

• based on data from thousands of cases, covering a wide range of sample donors.
• reviewed regularly to reflect advancements in drug testing technology
• designed to distinguish between actual drug use and incidental environmental exposure, preventing misleading conclusions

Our reports are not just data-driven but include expert analysis to help clients understand the significance of the results. Where results are close to the cut-off level, we provide additional insights to prevent misinterpretation.

Interpreting hair drug test results: a holistic approach

A hair drug test report provides a detailed analysis of drug use over a specified timeframe. However, the value of the report lies not only in the detection of substances but, more importantly, in the expert interpretation of the test results.

The results of a hair drug test should never be interpreted in isolation. Several factors can influence how drugs are incorporated into the hair, meaning expert analysis is essential to ensure a fair and accurate assessment.

Factors that AlphaBiolabs’ Reporting Scientists will always consider when reporting hair drug test results, include:

• Hair type and colour – studies have shown that melanin levels in hair can impact drug incorporation, meaning darker hair may sometimes retain higher concentrations of certain substances. This is partly the reason why it is not possible to precisely state the frequency of consumption, or the specific quantities of drugs consumed.
• Cosmetic treatments – it is well documented that chemical treatments such as excessive bleaching, dyeing, perming or straightening have the potential to affect drug retention in hair strands.
• External contamination – environmental exposure to drugs (e.g. through smoke or physical contact) does not necessarily indicate use. Our reports consider the presence of metabolites – byproducts produced by the body after drug use – to help distinguish between active consumption and contamination. We also ensure the hair being tested is thoroughly washed first to ensure any surface contaminants are removed/minimised.
• Biochemical properties of drugs – different drugs bind to hair at different rates, meaning some substances are more likely to be retained than others. This variation is considered when interpreting results.
• Variable growth rates of hair – AlphaBiolabs uses an average scalp hair growth rate of 1 cm/month as per the recommendation of the SoHT.

In summary, a hair drug test provides a scientifically-backed assessment of drug use over time, but it should always be evaluated alongside other evidence.

What’s included in an AlphaBiolabs hair drug test report?

At AlphaBiolabs, we are committed to delivering scientifically robust and transparent drug test results, ensuring that legal professionals, social workers and local authorities can rely on them with complete confidence.

Our reports provide context and expert interpretation, ensuring that results are not taken at face value but considered holistically. Our in-house Toxicology Reporting Scientists have graduate and post-graduate degrees in relevant subjects, together with a wealth of experience working both in family law, and within the field of forensic drug and alcohol testing.

Our hair drug test reports include:

• Sample donor information – including photo ID, and details of any disclosures made at the time of the sample collection (e.g. prescribed medications, drug/alcohol usage, environmental exposure to illicit drugs/close body contact with a drug user).
• Substances found and detected levels – which drugs have been detected, along with their concentration levels, measured in nanograms per milligram (ng/mg) or picograms per milligram (pg/mg) of hair (analyte dependent).
• Comparison with internationally-recognised cut-off levels – to ensure accuracy, the levels of substances detected are compared against scientifically validated thresholds. These cut-off levels play a fundamental role in helping to distinguish between actual drug use and potential external contamination. AlphaBiolabs also has analytical cut-offs for each analyte that are higher than the SoHT cut-offs to take into account analytical variation. Therefore, when a positive result is reported, there is no doubt that the compound is present within that tested sample.
• Interpretation of the test results, including relevant caveats and considerations – a drug test report should not simply tell you whether the sample donor has tested positive or negative for a certain substance. Our reports include expert analysis, considering factors such as possible external exposure to illicit substances, sample donor declarations, the presence of metabolites (which indicate active drug use), pattern assessments of active and previous drug use, and consideration of the natural variations in hair drug incorporation and rates of hair growth.
• Segmented analysis – if requested, hair samples can be segmented to provide an insight into a pattern of drug use over time, rather than a single result for the entire period (overview analysis).
• Contextual considerations – factors such as hair treatments, hair colour, sample donor declarations (such as prescribed medications/declared substance use), and the donor’s ethnicity are all carefully considered, to ensure a fair and accurate interpretation.

Fast, accurate and reliable hair drug testing

For those working in legal and safeguarding roles, partnering with a laboratory that delivers clear, transparent, and expertly interpreted drug test reports is essential.

At AlphaBiolabs, we are committed to providing the highest standard of drug testing, combining internationally recognised cut-off levels with expert analysis.

Our reports are designed with our customers in mind, providing legal professionals, social workers and local authorities with all the necessary details to support fair and accurate assessments.

More reasons to choose AlphaBiolabs for hair drug testing:

• Rapid results
• Widest range of drugs tested
• Legally defensible, user-friendly reports
• ISO 17025-accredited testing laboratory
• Member of the Society of Hair Testing with analysis carried out to internationally-agreed standards
• Our Price Promise: we will beat any like-for-like quote by a further 10%
• Expert advice and a dedicated Case Manager to fully manage your instruction
• Innovate and FREE Drug Screen Plus service
• Sample collections from any location within 24-48 hours of instruction
• FREE legally-instructed sample collections at our walk-in centres

To find out more or to request a quote, contact our New Enquiry team on 01 402 9466 / testing@alphabiolabs.com to discuss the requirements of your case.

Alternatively, complete our online quote form, and a member of the team will be in touch to discuss your needs.