Due to advances in research, technology and techniques, AlphaBiolabs is now able to offer alcohol testing for head hair samples that are just 1cm in length.  

This means if someone only has 1cm of head hair, we will still be able to test it and look for levels of the EtG biomarker in this hair sample. This can then be reported as excessive use of alcohol, or as a negative result.

The head hair sample must be a minimum of 1cm in length.  If the head hair is less than 1cm in length, we can test body hair (providing an overview of 12 months), fingernails (providing an overview of 6 months), or toenails (providing an overview of 12 months).

What is hair strand alcohol testing?

Alcohol testing is performed on hair samples every day across Ireland, mainly for use in legal matters – from local authorities making decisions about a child’s welfare, to family courts handling custody disputes.

Hair strand alcohol testing is one of the most effective ways of determining whether an individual has been drinking alcohol in excess. When used in conjunction with other tests, such as blood alcohol tests, it can help paint a complete picture of a person’s historic alcohol consumption.

How does hair strand alcohol testing work?

When a person consumes alcohol, it is absorbed into the bloodstream.  Most of the alcohol is broken down in the liver, and some of the alcohol metabolites find their way into hair and nails.

An AlphaBiolabs head hair alcohol test works by analysing head hair samples for the presence of two alcohol metabolites (biomarkers): ethyl glucuronide (EtG) and ethyl palmitate (EtPa), which is a fatty acid ethyl ester (FAEE). These biomarkers are absorbed into the hair via sweat and diffusion, and are present along the entire length of the hair.

Head hair typically grows at a rate of approximately one centimetre per month and, until recently, it has only been possible to provide a 3- or 6-month overview of alcohol use, depending on the length of hair sampled (3cm = approximately 3 months of hair growth and 6cm = approximately 6 months of hair growth). This meant that anyone with less than 3cm of head hair could not be tested for excessive use of alcohol using head hair samples.

However, advances in techniques and research now enable us to offer hair alcohol testing for head hair samples that are less than 3cm in length.  This means if someone has at least 1cm of head hair, we will be able to test it and look for levels of the EtG biomarker in this hair sample. This can then be reported as excessive use of alcohol, or as a negative result.

Combining hair alcohol testing with blood alcohol tests to give a fuller picture

As it is still not possible to test for the EtPa biomarker in hair samples under 3cm in length, we strongly recommend supporting the EtG result with one or more blood alcohol tests to give a fuller picture.

There are 4 main types of blood alcohol tests that can be used for legal purposes, all of which provide a 4-week historic overview of alcohol use:

  • Phosphatidylethanol (PEth) – a direct biomarker of alcohol
  • Carbohydrate Deficient Transferrin (CDT)
  • Liver Function Test (LFT)
  • Mean Corpuscular Volume (MCV)

CDT, LFT and MCV are all indirect biomarkers of alcohol, and their presence can be affected by pre-existing medical conditions and medications, among other factors.  However, PEth is a direct biomarker of alcohol.  This means that PEth is only present in the body when alcohol has been consumed and is by far the best option for an accurate and reliable result.

Alternative alcohol testing samples

If the length of head hair is less than 1cm, body hair or nails can also be used to test for the presence of EtG (but not EtPa).

Due to the rate at which body hair grows, the time period will be more approximate, with body hair (e.g. from the arm, chest or leg) providing us with up to a 12-month overview of alcohol use.

A nail test for alcohol can show abstinence during an approximate 6-month period for fingernails or 12-month period for toenails, by identifying whether or not EtG is present in the sample.

Both body hair and nail testing for alcohol should also be supported by one or more blood tests.

Where can I get an alcohol test?

As an ISO 17025-accredited alcohol testing laboratory, we are well placed to support you with your alcohol testing needs, whether you are a:

Our laboratory is fully equipped to test a variety of samples for the presence of alcohol including blood, hair, and nails. We also offer point-of-care breath tests, as well as alcohol monitoring using SCRAM CAM®. 

For more information, contact our friendly and discreet Customer Services team on 0140 29466 or email

Alcohol Testing Services

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