A hair strand test (HST) for alcohol involves testing a section of an individual’s head hair for biological markers of alcohol consumption. HST for alcohol is the most common form of testing for alcohol. 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 depending on the length of hair strand analysed.

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

AlphaBiolabs analyses two direct markers in its HST for alcohol. Ethyl glucuronide (EtG) and a fatty acid ethyl ester (FAEE) called ethyl palmitate (EtPa). Both of these are specific long-term markers of ethanol, which is the intoxicating agent in alcohol.

How does HST for alcohol work?

The minimum length of hair needed for a HST for alcohol 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 biomarkers EtG and EtPa are absorbed via different routes and their levels can assist in assessing excessive alcohol use. AlphaBiolabs analyses both markers 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 water soluble, which means that some EtG may be lost through the use of hair dye and excessive hair washing.

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

Because of the respective strengths and weaknesses of EtG and EtPa, both tests should be performed and their findings should support each other in order to determine chronic excessive consumption of alcohol.

Although, AlphaBiolabs’ HST for alcohol methods are highly accurate and reliable, we would always recommend that a blood test also be taken. This complements the EtG/EtPa alcohol test and, especially in cases of inconclusive results, can provide a greater insight into an individual’s level of alcohol consumption.

AlphaBiolabs provides a range of alcohol testing solutions in addition to HST for alcohol. These include blood alcohol tests, instant breath tests , nail clipping and body hair analysis. Real-time results are also available with SCRAM Continuous Alcohol Monitoring®. For expert advice, please call Customer Services on 0333 600 1300 or email us at