Hair drug testing vs hair alcohol testing
Both hair drug testing and hair alcohol testing can be used to paint a clear picture of an individual’s historic drug and/or alcohol consumption.
However, while both tests rely on the analysis of head hair or body hair samples, there are several fundamental differences between the two tests.
In this article, we look at hair drug testing versus hair alcohol testing, the benefits of each test, and what the results can tell us about a person’s drug or alcohol use.
- What is a hair drug test?
- What is a hair alcohol test?
- What happens in the body when a person consumes drugs?
- What happens in the body when a person consumes alcohol?
- What is the difference between a hair drug test and a hair alcohol test?
- How is a sample collected for hair drug testing and hair alcohol testing?
- What does a hair drug test look for?
- What’s included in an AlphaBiolabs hair drug test report?
- Why are cut-off levels important for hair drug testing?
- What does a hair alcohol test look for?
- How much do court-approved hair drug tests and hair alcohol tests cost?
- How accurate is hair drug testing and alcohol testing?
- What can affect the results of a hair strand test for drugs?
- What can affect the results of a hair strand test for alcohol?
- Where can I get a hair test for drugs and/or alcohol?
What is a hair drug test?
A hair drug test, also known as a hair strand test or a hair follicle test, involves analysing samples of head hair or body hair for the presence of drugs and their metabolites.
When a person consumes drugs, they are passed into the bloodstream, and the parent drug and a proportion of the drug’s metabolites enter the hair follicle.
When the hair is subjected to analysis at the toxicology laboratory the parent drug and its metabolites can be identified within the hair.
What is a hair alcohol test?
A hair alcohol test involves analysing samples of head hair or body hair for the presence of alcohol biomarkers.
There are two biomarkers of alcohol that we look for during an AlphaBiolabs head hair alcohol test: ethyl glucuronide (EtG) and ethyl palmitate (EtPa), which is a fatty acid ethyl ester (FAEE).
If head hair is unavailable, body hair can be used to test for the presence of EtG.
However, due to the way in which ethyl palmitate (EtPa) is incorporated into hair, body hair can only be used to test for EtG, not EtPa.
This is because EtG and EtPa are incorporated into the hair in different ways when alcohol is consumed: EtG via sweat, and EtPa via sebum, an oily substance secreted by glands in the scalp.
We do not have the same oil glands on our body that we do on our heads, meaning body hair testing for EtPa is not possible.
What happens in the body when a person consumes drugs?
When a person consumes drugs, they are broken down by the liver, and a proportion of the parent drug and its metabolites are released into the bloodstream, before being excreted from the body in a variety of ways.
This makes it possible to analyse a variety of samples for the presence of drugs and their metabolites, including hair, nails, oral fluid (saliva), and urine.
Although methods such as urine or oral fluid testing can only show us what a person has consumed in the past couple of days, the rate at which hair grows means that hair drug testing can provide us with a ‘wide window’ of detection for drugs and their metabolites (up to 12 months).
The same principle applies for nails, with nail drug testing also offering a window of detection up 12 months.
What happens in the body when a person consumes alcohol?
When a person consumes alcohol, it is absorbed into the bloodstream, and around 90% of it is broken down in the liver.
The rest is passed out of the body in sweat, urine, and exhaled breath.
This makes it possible for toxicologists to analyse a variety of samples for the presence of alcohol biomarkers including hair and nails.
Alternatively, breathalyser devices can be used to detect alcohol in breath, while alcohol monitoring devices such as the SCRAM CAM® – an ankle monitor that can detect alcohol in sweat – can be used as a form of continuous alcohol monitoring.
What is the difference between a hair drug test and a hair alcohol test?
Although both test types use hair samples, there are several fundamental differences between a hair alcohol test and a hair drug test.
The most obvious being that each test is used to detect different substances.
However, there are other key differences including:
Detection windows
The detection window for drugs or alcohol refers to the length of time substances remain detectable in an individual’s sample after consumption.
A drug test using head hair can be used to detect drug use for a period of up to 12 months prior to collection of the hair sample, with two types of analysis offered if the donor has sufficient head hair: segmented (month-by-month) or overview analysis.
However, a hair alcohol test can only be used to provide a three- or- six-month overview of alcohol consumption.
This is because drugs and alcohol find their way into the hair in different ways.
When a person consumes drugs, they are broken down by the liver, and a proportion of the parent drug and its metabolites are released into the bloodstream.
These drugs then enter the hair follicle and become trapped in the medulla, the innermost layer of the hair shaft.
As the hair grows, the drugs remain in the hair, meaning segmentation analysis can be used on head hair to determine a pattern of drug use over a defined period, depending on the length of hair selected (1cm of hair = one month of growth).
Head hair can be used to provide up to 12 months of segmented analysis. Again, this is dependent on the length of hair available.
Alternatively, overview analysis can be used to obtain a more general insight into a person’s drug use. This is because episodes of drug use are averaged out over the period being tested.
Head hair or body hair can be used to provide an overview of up to 12 months of drug use.
When a person consumes alcohol, it is absorbed into the bloodstream, and around 90% of it is broken down in the liver.
The remainder is then passed out of the body in a variety of ways including in sweat and exhaled breath.
Unlike drugs, which become trapped in the hair, alcohol biomarkers are deposited onto the hair via sweat and diffusion and are present along the entire length of the hair.
This means it is not possible to segment the hair for alcohol testing – it is only possible to perform overview analysis (three- or six-months).
The level of biomarkers on the hair can also be impacted by external factors such as hair treatments or the use of hair products containing alcohol.
What the test report will show
A hair drug test report will show which drugs are present in the hair sample (above cut-off guidelines) for the period prior to samples being collected.
Depending on whether you have chosen segmented or overview analysis, the report will either show month-by-month results for each 1cm segment of hair (up to 12 months) or an overview of the substances detected during a defined period.
A hair alcohol test report will show whether alcohol biomarkers were present in the hair sample (above cut-off guidelines) for the period prior to samples being collected (three- or six-month overview).
AlphaBiolabs follows cut-off guidelines for hair alcohol testing and hair drug testing, as set by the Society of Hair Testing (SoHT).
How is a sample collected for hair drug testing and hair alcohol testing?
Samples for legally-instructed hair drug tests or hair alcohol tests are usually collected by a trained sample collector, under chain of custody conditions, ensuring the samples are collected from the right people, and preventing sample tampering.
The hair sample needs to be cut from the highest point of the scalp (the vertex) as this region is associated with the least variation in growth rates.
Ideally, the sample needs to contain around 200 individual strands and should always be taken from a discreet area if possible.
Hair samples are usually taken from a person’s head. However, if head hair is not available, body hair can be collected from the underarm, leg, chest, or face, for an overview of up to 12 months.
What does a hair drug test look for?
A court-approved hair drug test looks for the presence of drugs and their metabolites in a cut sample of head hair or body hair.
The following are the main drugs we test for during an AlphaBiolabs hair strand drug test, depending on the requirements of the instructing party.
- Amphetamine
- Benzodiazepines
- Buprenorphine
- Cannabis
- Cocaine
- Ecstasy (MDMA)
- Ketamine
- Mephedrone
- Methadone
- Methamphetamine
- Opiates
- Phencyclidine
- Zolpidem
For an even more thorough insight, we also offer a Drug Screen Plus service that will tell you whether any additional substances were present that you did not specifically ask us to test for at the time of instruction (see What is Drug Screen Plus?)
We can also arrange hair drug testing for GHB, LSD, Spice, steroids, and Tramadol, for an additional fee.
What’s included in an AlphaBiolabs hair drug test report?
We are committed to delivering scientifically robust and transparent drug test results.
Our reports provide context and expert interpretation, ensuring that results are not taken at face value but considered holistically.
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).
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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.
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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.
Why are cut-off levels important for hair drug testing?
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.
What does a hair alcohol test look for?
A hair alcohol test using head hair looks for the presence of two alcohol biomarkers: ethyl glucuronide (EtG) and ethyl palmitate (EtPa), a fatty acid ethyl ester (FAEE).
Both are direct biomarkers of alcohol, meaning that they can only be formed in the body when ethanol – the intoxicating agent in alcoholic drinks – has been consumed.
If head hair is unavailable, body hair can be used instead, but can only be used to detect the presence of EtG.
This is because EtPa is primarily deposited onto the hair via oil (sebaceous) glands, while EtG is deposited via sweat glands. As we do not have the same oil glands on our bodies as we do on our scalps, an alcohol test using body hair can only be used to detect EtG.
AlphaBiolabs follows the Society of Hair Testing guidelines for cut-off levels (where applicable) for hair sample types.
How much do court-approved hair drug tests and hair alcohol tests cost?
The cost of a hair drug test and/or a hair alcohol test varies depending on the requirements of the instructing party.
To request a quote for hair drug testing and/or hair alcohol testing, simply complete our online form, and a member of our Legal sales team will be in touch to discuss your needs.
You can also call 01 402 9466 or email testing@alphabiolabs.com for more information.
If you have received a quote for hair drug testing or hair alcohol testing from another testing laboratory, we will match their price and reduce it by a further 5%: this makes AlphaBiolabs the most cost-effective solution for your legal drug and/or alcohol testing needs.
How accurate is hair drug testing and alcohol testing?
Our hair follicle drug testing and hair follicle alcohol testing is 100% accurate and reliable based on the samples we receive at our laboratory.
Here are just a few reasons why you can trust AlphaBiolabs for hair drug and alcohol testing:
- We have over 15 years’ experience providing first-class drug and alcohol testing services for the legal sector
- We have invested in the very latest technology for our state-of-the-art toxicology laboratory
- We employ some of the foremost scientists in their field of expertise
- We follow cut-off guidelines for hair drug and alcohol testing, as set by the Society of Hair Testing (SoHT)
- Our laboratory is accredited to the quality technical standard of ISO 17025 (No. 2773) and certified to ISO 9001
- All our legal sample collections are carried out by professional sample collectors, under chain of custody conditions
What can affect the results of a hair strand test for drugs?
Certain hair treatments including bleaching, dyeing, perming, and straightening have the potential to impact the results of a hair drug test.
For this reason, reputable testing laboratories like AlphaBiolabs will always ask for full disclosure of any recent hair treatments so that this can be taken into consideration when preparing the results.
What can affect the results of a hair strand test for alcohol?
Ethyl glucuronide (EtG) and ethyl palmitate (EtPa), both alcohol biomarkers that can be detected in a hair sample during hair alcohol testing, can be affected by different external factors.
EtG is water soluble and is deposited onto the hair via sweat glands.
This means that hair treatments such as bleaching, dyeing, perming, straightening, and excessive washing all have the potential to reduce the levels of EtG found on the hair.
EtPa is a fatty acid ethyl ester (FAEE) and is lipophilic (fat soluble).
Although styling methods such as bleaching, perming, dyeing etc. will not significantly affect EtPa levels (unless aggressively used), hair styling products that contain alcohol such as hairspray, gel and wax can increase the levels of EtPa found during laboratory analysis.
The sample collector will always ask the donor to disclose details of any recent hair treatments that have the potential to impact the results.
This information will be considered when preparing the results.
The donor is also advised not to use any alcohol-based styling products for at least one month prior to sample collection, to reduce the likelihood of an elevated EtPa result.
Where can I get a hair test for drugs and/or alcohol?
AlphaBiolabs has extensive experience providing drug and alcohol testing services for local authorities, family law professionals and social workers.
We have invested in the very latest technology for our state-of-the-art toxicology laboratory, employing the very best scientists, so you can be confident of receiving a 100 per cent accurate result.
All sample collections are performed under strict chain of custody conditions, and our drug and alcohol test results are accepted by courts.
We also offer free sample collection for legally-instructed hair drug tests and hair alcohol tests from our Dublin walk-in centre.
For expert advice or to request a quote for hair drug/alcohol testing, call our Legal team on 01 402 9466 or email testing@alphabiolabs.com.

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