A hair follicle test for alcohol analyses two biological markers of alcohol consumption in a hair strand sample.

There are two types of biological marker of alcohol: direct and indirect. Direct markers, as their name implies, directly track the intake of alcohol and vary in their sensitivity and kinetics accordingly. These direct markers are only produced when a person has drunk alcohol. This means that the amount of alcohol consumed will determine their levels, which ensures accuracy when establishing levels of alcohol consumption. Indirect markers are biological parameters that are influenced by a steady and significant alcohol intake. However, indirect markers are less accurate because they can be affected by other factors, such as medication and health issues.

AlphaBiolabs’ hair follicle tests for alcohol measure two markers: ethyl glucuronide (EtG) and the fatty acid ethyl ester (FAEE) ethyl palmitate (EtPa).

The markers EtG and EtPa are absorbed via different routes and their levels can assist in assessing excessive alcohol use by an individual. Both markers are analysed because they are affected by external factors in different ways. EtG is produced by the liver and incorporated into the hair, mainly through sweat. It is hydrophilic, meaning that it is water soluble. As such, some EtG may be lost through the use of hair dye, bleaching, perming and excessive hair washing.

EtPa and all FAEEs are produced in the blood and incorporated into hair via sebum (an oily substance secreted by glands in the skin). FAEEs are lipophilic and therefore not water soluble, so although not affected by hair washing, the amount detected could be affected by use of hairsprays, wax and gel if they contain alcohol.

Because of the respective strengths and weaknesses of EtG and EtPa tests, both tests should be performed and their findings should support each other in order to determine chronic excessive consumption of alcohol. However, as EtG is the more reliable of the two markers, a positive EtG result alone can be reported as chronic, excessive use of alcohol.

How do hair follicle tests for alcohol work?

The minimum length of hair for EtG and EtPa tests is a 3-cm section taken from nearest the scalp. Around 200 individual strands are required, which is about the width of a pencil. AlphaBiolabs follows the consensus on hair alcohol testing for chronic excessive alcohol consumption published by the Society of Hair Testing (SoHT). The result will be considered either above or below the recommended SoHT cut-off levels. The level of biomarker found in the hair can help determine if a person has been drinking chronically and excessively, and will show an overview of 3 or 6 months.

Although, AlphaBiolabs’ hair follicle tests for alcohol are highly accurate and reliable, we would always recommend that a blood test be taken to complement the EtG/EtPa test. This is to support the hair results and, especially in cases of inconclusive results, to provide a greater insight into an individual’s level of alcohol consumption.

As well as hair follicle tests for alcohol, AlphaBiolabs provides breath, blood and nail alcohol testing. We also offer round-the-clock testing via SCRAM Continuous Alcohol Monitoring®. For expert advice or further information, please call 0333 600 1300 or email us at